If you’ve gone shopping for a cell phone lately, you’ve probably encountered a salesman who couldn’t contain his excitement about “4G.” That’s the name given to several technologies that are supposed to allow for much faster and more reliable wireless Internet connections. If you believe cell companies’ ads, 4G is going to change your life—you’ll be able to videoconference from the beach, show up your colleagues in front of your boss, and finally get along with your kids.

I’m sure there’s some truth to this. As the nation’s largest carriers roll out 4G coverage over the next few years, and as cell phone companies come out with better 4G phones, we probably will get pretty great service. Right now, though, be wary of claims of 4G heaven. Often, it’s nothing more than a marketing gimmick. To see what I mean, look no further than MetroPCS.

Last September, the carrier best known for its low-cost, no-contract wireless service surprised many in the phone business with its plan to begin supplying 4G coverage across its network. MetroPCS’$2 4G is based on a technology called LTE, which is the same system that the nation’s largest carriers—AT&T and Verizon—plan to roll out over the next few years. So how is MetroPCS able to offer LTE right now? And not only that: How can MetroPCS offer 4G for so little money? Depending on the features you’re looking for, you can get a MetroPCS 4G plan for $40, $50, or $60 a month, taxes included, and without signing a contract. In other words, MetroPCS’ most expensive 4G plan is cheaper than most other carriers’ least expensive 3G plans. That sounded too good to be true. And, boy, was it ever.

I’ve been using the Samsung Craft, MetroPCS’ first and only 4G phone, for a couple weeks now. It’s a nightmare. I’d call it the worst cell phone I’ve ever used, but to do so would woefully undersell the sadists who’ve unleashed this little gadget of horrors upon an unsuspecting public. Everything about this phone seems designed not just to frustrate users but to get us to swear off ever using any phone again. Yes, the Craft is so terrible that I’ve started to spin conspiracy theories around its release. Specifically, I wonder whether MetroPCS is trying to get us all bummed out about the possibilities of 4G so that it can forgo any major improvements in its network. After all, if this is what 4G is like, maybe we should all stop whining and stick with what we’ve got now.

To take just one example of what makes the Craft truly dreadful, let me tell you about its Web browser. Do you ever feel nostalgic for the early 2000s, when phones offered “Web access” that always seemed to mangle whatever site you visited? If so, you’re in luck, because that’s just how it is on the Craft! The phone’s browser lacks most of the technologies that go into modern sites. It won’t do Javascript, for example, so the full versions of sites like Google Maps don’t work. It won’t play video from most sites, either. And because most Web sites recognize that you’re coming from a super-dumb phone, they serve up low-fi versions of their pages, meaning you’ll see text and low-res graphics on most of the Web’s major destinations.

Even when you do get to a site that doesn’t look terrible—Slate looked OK on the Craft—you’ll find yourself fumbling with the browser’s interface. How do you click on a link? Do you hit the touch screen? Yes, sometimes. Other times hitting the screen seems to make it zoom in on the site. Other times tapping does nothing at all. At this point you’ll start hitting the screen repeatedly with a hammer or rolling pin. That doesn’t seem to work, either.

What’s the point of having an amazingly fast 4G Internet connection if your phone can barely crawl onto the Web? I’m not really sure. As part of its $40 plan, MetroPCS throws in “unlimited YouTube” access as well. This should sound suspicious on its face; isn’t YouTube covered in the “unlimited Web” access that you’re paying for? Apparently not. The “unlimited” Web, as MetroPCS defines it, doesn’t include most Web video; MetroPCS is throwing in YouTube as an added bonus. This definition has landed MetroPCS in trouble with consumer advocates, who say that offering the “unlimited Web” while blocking all video sites other than YouTube is a violation of network neutrality rules. MetroPCS declined my request to interview an executive about that allegation. The company made its feelings on network neutrality pretty clear late last month, though, when it filed a lawsuit against the FCC to challenge the rules.

Whatever its legality, YouTube on the Craft is one of the phone’s better features. That is to say, it’s still pretty terrible but not quite completely unusable. The 4G network does seem to result in extremely fast video streaming—clips start playing immediately, without hiccups, much faster than YouTube over 3G on my AT&T iPhone. There’s just one small problem: The videos are ugly. Even when you select high-definition YouTube streams, you’re presented with grainy, blurry, low-res clips that—bizarrely—don’t take up the phone’s full screen.

MetroPCS’ more expensive 4G plans offer some additional features that benefit from the faster network. Under the $60 plan, you get access to MetroSTUDIO, which allows you to stream popular TV shows. These videos looked slightly better than YouTube clips, but not great by any means, and certainly not worth the extra $20 a month.

But, wait, it gets worse. MetroPCS’$2 4G service is available in only 13 cities. So what happens when you’re in a place without 4G? Things get much, much slower. MetroPCS offers 3G service only in Dallas and Detroit; everywhere else, it uses what people call 2G networking, wherein Internet speeds are comparable to dial-up. So if you take your 4G phone anyplace without superfast coverage, you’ll get superslow coverage.

And that’s not all. The Samsung Craft costs an astounding $299, which is $100 more than you’ll pay for an actually useful smartphone like the iPhone or the Droid. It’s also at least $500 more than it’s worth. The Craft: a cell phone so bad you couldn’t pay me to use it.

Become a fan of Slate and Farhad Manjoo on Facebook. Follow us on Twitter.