Jessica Dolcourt/CNET

A week ago, I trudged through a cold drizzle, coffee clutched desperately in hand, to test Verizon's new 5G network the day after it launched in parts of downtown Chicago and Minneapolis. After using it for six solid hours on the Moto Z3 and its 5G Moto Mod in Chicago, I walked away with a clearer understanding of the biggest issues facing Verizon and other carriers as the next-generation data networks begin to roll out.

I'd like to be able to say that using Verizon's 5G was a mind-blowing experience, with download speeds beyond my wildest imagination. I wish I could tell you that I downloaded entire albums of music and streamed video instantly. Unfortunately, all I can say after a long day is that I found it confusing. Frustrating. Absolutely insane. The new network isn't a silver bullet that will magically make your data dreams come true, and it won't be for some time. It faces growing pains, and we're going to have to grow right along with it.

At times, the 5G speeds recorded by the Speedtest.net benchmarking test got us the 600-plus megabits per second download speeds Verizon has promised (my peak speed was 634Mbps). Other times it was closer to 200Mbps, and still other times, the phone professed to be on 5G, but acted a lot like 4G. I had a battalion of upload and download tests I was going to try Thursday in downtown Chicago, but it was so hard to keep a 5G connection long enough to run the most basic tests, I had to throw those plans out the window.

Verizon and Motorola are well aware of these issues. I spent hours with PR reps from both companies, and kept in close contact with them throughout the day. They both acknowledged the start-up issues and said that engineers were following up with trouble locations.

Now playing: Watch this: We tested Verizon's new 5G network

That's not a great start, and it indicates that something isn't working well -- the network, the phone, the Moto Mod attachment or the way they all come together. It's an awkward place to be for a network boasting to be the world's first live 5G network.

Read: Verizon defends its 5G network's rocky start, but it has a plan

Despite it all, I'm still excited about the prospect of 5G, and Verizon, like all the other carriers, will have a major role to play. 5G's potential isn't just about ultrafast downloads, though those are great, too. It's about all these other things that speed and massive bandwidth enable: crystal-clear video calls with no lag. Incredible AR and VR experiences that don't make you feel woozy. Smart cities where self-driving cars and traffic lights talk to each other.

5G just hatched, and while that doesn't change my initial testing experience, it's worth remembering that this is the direction we're all headed in, and it will get better.

Screenshot by Jessica Dolcourt/CNET

That said, Verizon does seem to have jumped the gun by turning on 5G earlier than its April 11 target, a move that underscores the carrier's belief that acting quickly and aggressively in 5G will give its network, already the largest in the US, a first-mover advantage. 5G, the next-generation wireless technology, is widely championed as the cure to laggy data connections and slow phone download speeds.

5G is positioned to revolutionize the industry, increase data connections from 10 to 100 times the current 4G speeds and enable a host of new uses, like distance surgery and smart traffic lights that talk to one another to keep traffic flowing smoothly.

That's not what I saw. But to be fair, neither was I expecting mind-blowing speeds. Again, 5G is a brand-new technology, prone to pitfalls, stumbling blocks and rough edges. Verizon has been very clear about the limited coverage areas, and has promised that it'll cover parts of 30 cities with 5G speeds by the end of 2019. While 5G comes online for the first time in one city, network engineers will also expand service in, say, Chicago.

5G speeds are also expected to easily top 4G, gaining momentum as carriers build out their 5G networks over time. I spent the day all over downtown Chicago to test real-life 5G speeds, far from carefully constructed demos. Here's what happened: the good, the bad and the aggravating.

Read: Galaxy S10 5G and Verizon's 5G launch get up in your face with next-gen speeds

Derek Poore/CNET

A word on 5G before we begin

5G isn't just one thing. There are multiple approaches. Sub-6. Millimeter wave (mmWave). AT&T has even been accused of (and sued for) "fake 5G." With this new world of 5G comes a cosmos of new jargon.

For example, Verizon's 5G network uses the 28GHz and 39GHz bands for mmWave to bring 1GHz of bandwidth on average nationally. If that doesn't mean much to you, it might help to get up to date with our 5G primer.

A word on the Moto Z3 with 5G Moto Mod

We also need to talk about this Moto Z3 for a minute. It's a midrange device that is able to channel Verizon's 5G network through the power of a chunky "fin" sticking out the top and the internal modem inside the 5G Moto Mod, which is sold separately.

Jessica Dolcourt/CNET

The Mod has four mmWave antennas and infrared sensors that signal the right antenna to kick into gear. Say you're blocking three with your hands, the fourth will take over.

The Moto Z3 is on sale now at $240 (usually $480); the Moto Mod is also on sale now at $200 (usually $350), and you have to have a Z3 on your account to buy it. Verizon 5G service is a $10 premium over the regular plan, but your first three months are free.

Read: Motorola defends Mod attachment as the best 5G platform. I disagree

The road to testing hell is paved with good intentions

The day began cheerily enough, with a visit to Verizon's big store on Michigan Avenue. Just after its 10 a.m. opening, workers on ladders were just beginning to unpeel giant "5G" stickers on the windows. Three digital screens exclaimed, "It's here! It's here! It's here!"

Verizon's friendly PR reps handed out test phones and pointed to a large black rectangle affixed to a wall near the entrance -- this was the 5G "node," a part of the network that delivers 5G speeds to the store. If your 5G device is within line of sight, it should receive Verizon's fastest data speeds. Verizon says to expect "typical speeds of 450Mbps, with peak speeds of nearly 1Gbps, and latency less than 30 milliseconds."

Derek Poore/CNET

It was immediately clear this wouldn't be the case. Even carefully positioned a few feet away from the 5G node, the large on-screen icon exclaiming Verizon's 5G network toggled back and forth from 4G to 5G. It felt like all I had to do was move the phone or look at it funny and the 5G UWB (Ultra Wideband) insignia would flicker away. After two hours, we had run maybe one clean speed test side by side with the Galaxy S10 Plus.

At the same time we were trying our luck upstairs, a "SWAT team" of troubleshooting engineers from Verizon, Motorola, Qualcomm (the chipmaker) and Ericsson (which makes the networking infrastructure gear) swarmed the store. Apparently the node was acting up. Time to move on.

Fast benchmarking speeds but real-world failures

The second and third stops were better, at least as far as the benchmarking went. The second speed test took place across the street from the Merchant Mart, which is home to Motorola's headquarters. It was standing outside in a valet lot in the rain that we were able to see those blazing 5G download speeds, at least some of the time.

A couple times I saw theoretical download speeds kissing 600Mbps. Other times, the download would start strong, the phone would flicker to show the 4G logo, and speeds would plummet. And still other times, the 5G logo was on, but speeds fell in between the two.

Speed tests from the Moto Z3 on Verizon's 5G network, taken at multiple locations throughout Chicago, but all close to 5G nodes if not directly underneath them. You can see how speeds vary @CNET pic.twitter.com/qsEgrIK81i — Jessica Dolcourt (@jdolcourt) April 5, 2019

Real world test 1: Downloading a large file

It's here outside Motorola's HQ that I was finally able to try my first real-world test: downloading the game PUBG. It's a large, 1.81GB file, which took roughly 5 minutes, 45 seconds to download with the 5G icon going strong. Then I uninstalled the app, took off the Mod to ensure 4G LTE speeds only, reinstalled it over data and... it took exactly the same time. That was unexpected, especially since reviewers from other outlets experienced faster download speeds.

Uplink is the same on 5G and 4G, Verizon said, at least for now.

Real world test 2: Downloading a Netflix show

The preeminent scenario for the 5G dream is being able to download entire seasons of Netflix from the time you walk down the airplane gangplank to the time you settle into your seat. Ditto downloading a big presentation or a bunch of photos before you're forced to go offline.

This would be the perfect test for our third location, the intersection of Michigan and Monroe outside the famous Art Institute of Chicago. Once again standing directly below the node (outdoors, they're attached to street lights), we ran a few speed tests for a baseline, and then attempted to download a 50-minute episode of Planet Earth II from Netflix.

Derek Poore/CNET

With the 5G logo on full display, we turned on the stopwatch using another phone and watched the progress pie chart inch forward a sliver, and then another, and then... nothing. After several more attempts, we tried it again in 4G, with the Moto Mod taken off. The result was identical: a sliver of progress, followed by the same stalling for minutes. After 20 minutes in the rain, it was time to try our luck at one more spot.

Real-world test... oh, forget it

Our final test site was a total bust. A few blocks from the famous Chicago Theater, I stood beneath the 5G node and tried every reboot, cycling and reattachment trick for a good 5 minutes. Nothing happened. I tried again. Still nothing happened. I reported it to Verizon's SWAT team and called it a day.

What happened to all the other tests I planned?

Like I said earlier, I started the day fresh-faced and caffeinated with a plan to throw loads of comparison speed tests, lots of downloads and gameplay at the Moto Z3.

The problem is that it took too long to lock onto a strong enough 5G network to complete one task that there wasn't time for the rest, especially if we wanted to check out four different locations around the city -- and we did, to get a sense of Verizon's real-world deployment of 5G coverage.

Now playing: Watch this: 5G phone speeds will give you whiplash

If 5G repeatedly cuts out and cycling airplane mode, disconnecting and reconnecting the Moto Mod and even rebooting the phone won't reliably bring it back again, how can you accurately assess the impact of downloading large files or play resource-heavy games? You can't. Those deeper tests will have to wait for a more stable network.

3 big, unacceptable problems and how to fix them

Any way you slice it, this was a disaster of a launch. Yes, Verizon was first in the US to launch a "real", commercial 5G network for phones, but at what cost? The journalists who came to Chicago spent all day outside in cold, rainy weather with very little to show for it. While speed tests worked in some locations, real downloads weren't any faster, even when standing directly beneath a node.

As far as I can tell, three things went majorly wrong.

The flickering 5G icon

Hours after our testing day was done, Verizon informed us that the 5G logo only turns on when you're actually using 5G. So switching rapidly between the two logos is a sign that the 5G network is engaged. It dips back to the 4G logo any other time.

I don't buy that. When 4G butted in during speed tests, the downlink speeds on the screen fell sharply, in line with 4G speeds. If 5G returned while the test ran, speeds picked up. That doesn't fall in line with the engineers' explanation.

The fix: Assuming that's the case and not a line, Verizon needs a persistent 5G icon -- just like the 4G icon now -- so people know they can access those speeds. What else are they paying $10 a month more for?

Derek Poore/CNET

The time the Moto Mod died and I didn't know it

Remember that final location near the Chicago Theater where 5G didn't work at all, no matter what I tried? What I realized later was that the Moto Mod was dead. Motorola gave the 5G Mod its own 2,000-mAh battery, and when it goes, so does 5G.

Yes, there's a battery indicator on the screen, but that's for the phone itself. There's no other visual meter showing the Mod's battery life. There is, however, a notification that appears, along with all your other notifications.

Motorola also says it shows you a temporary notification on the home screen that the battery life on the Mod is dead. Maybe the phone was in my purse while I was en route. Maybe I looked away when it flashed. For whatever reason, I didn't see it.

I agree that having a dead Mod suck power from your phone's battery isn't the right move, at least not without your permission. If 5G dies, no big deal, you can live with 4G speeds. But if your phone dies as a result of fueling 5G, then you're really in trouble.

The fix: Like Verizon, Motorola needs a lesson in better communication. A battery indicator for the Mod is a must, and it's got to stand out as distinct from the phone's battery indicator. Also, any future Mod (and OMG, I hope there's never another one like this) needs to offer to share battery if you have plenty to spare.

Verizon's rush job

In its rush to be first to 5G, Verizon appears to have thrown its hands up and hoped for the best. The utter breakdown and embarrassment of this day will pass. Verizon is playing a long game. And there is an advantage to rolling out 5G first.

However, on-the-spot troubleshooting doesn't make Verizon look particularly capable or smart, even if a massive amount of technical skill and planning went into the deployment. It would have been better to wait a week, for a better showing.

The fix: Unfortunately, Verizon can't Back to the Future us to Tuesday when it apparently had its go/no go launch meeting. But it can throw resources (aka tons of money and people) at working on its mistakes before human guinea pigs pay good money for irregular and unreliable 5G.

Verizon should be prepared to credit early adopters for uneven service as a reward for sticking through what's almost guaranteed to be some turbulent times.

Andrew Hoyle/CNET

What I learned, and what it means for you

I can't speak for the folks who sampled Verizon's 5G launch in Minneapolis, but this experience in Chicago underscores the rocky road ahead for 5G. The new technology isn't unique in having a rough start. The same happened when we transitioned from 3G to 4G. It's par for the course.

But maybe there are some new lessons here, primarily that networks and phone brands need to make it crystal clear when you're receiving 5G and when you're not.

I'm still excited about 5G once the carriers work out big kinks. But I can't recommend a 5G phone in the near future based on this experience.

Before you rush to join the 5G revolution, think carefully about your options. Consult a coverage map. Do the math to see how much more it will cost. Look into what's down the road. Qualcomm has a smaller chip for 2019's 5G phones that will make the Mod and even the Galaxy S10 5G obsolete. Phones, too, will get cheaper over time.

My first 5G tests marked an unforgettable look at our 5G future. But it's not the version of our 5G future that anyone really wants.

Originally published April 4 at 8:20 a.m. PT and updated frequently.