A few nights after I got the new Weber Genesis II LX grill on my roof deck, I texted my buddy Ted, proposing beer and burgers at my place. I've reviewed Weber's grills before and fully expected this one, the latest addition to its line of sturdy and well-made propane grills, to stand out as a high-end weekend warrior.

“Oh, hell yes!” Ted replied less than a minute later. Gentleman that he is, he even brought the beer.

I crisped up buns on the hot grate and grilled thumb-thick patties, giving one side more time than the other in order to brown them while avoiding what my dad would call "cooking it into a coma." They made for some pretty fantastic weeknight burgers. But after more rigorous testing, the grill proved to have some serious weaknesses. This thing is built like a tank, but it's surprisingly underpowered.

Next in Line

The Genesis II follows Weber's hallowed three-burner Genesis line, and there’s some nice thinking here. Along with the quality you’d expect from Weber—these are the guys behind the famous Weber kettle grill, the highly lauded, gas-powered Spirit line, and exciting newer models like the kamado-style Weber Summit Charcoal—this grill comes with a fancy new "grease management system." Laugh if you will, but anyone who’s ever gone after a long-neglected grease pan with a putty knife or accidentally lit a grease tray ablaze while preheating will appreciate a grill that funnels grease toward a disposable drip pan.

I reviewed a grill in the LX series, which comes with a few more BTUs of heat and some additional bells and whistles. (The Genesis II line includes eight models altogether.) There's a stainless-steel grill grate, a storage cabinet beneath the grill, and a light that attaches to the lid handle to illuminate whatever you’re cooking. You can find similar features in other grills or buy them as after-market add-ons, but having them built into the model is a nice touch.

Less necessary are little LEDs that light up the dials. I turned them on and the button immediately got stuck. As far as I know, it's still stuck and the lights are still on. There’s also an LED that indicates how full the propane tank is, but it’s right around the corner from the manual tank scale that tells you, at a glance, how full the propane tank is. So, there are two fuel gauges right next to each other, which display exactly the same information.

The grill is also “iGrill 3 Ready,” which is to say, you can buy an iGrill 3—a type of remote thermometer—and stick it in the spot where the LED gas gauge goes. But I wouldn’t. iGrills can monitor the temperature of a couple things at once—say, the interior temperature of a thick cut and the temperature inside the grill—and deliver that information to an app on your phone via Bluetooth. The problem is that iGrill 3 has no built-in readout. That means if you're standing in front of the grill, you'd have to open an app just to read the temperature on the thermometer directly under your nose. Apps and Bluetooth connections can be great additions to cooking hardware, but in cases like this, they also get in the way. The iGrill 2 has an easy-to-read LED on its base that displays temperature; having no readout on the iGrill 3 is straight-up dumb.

Blown Away

One of the best ways to test a grill's capabilities is setting it up for two-zone grilling. Indirect cooking relies on getting the temperature to hold at specific points, whether it’s just to cook a chicken breast through or the hours-long process of cooking pork butt. You’re not searing—just using the grill like an oven to cook the food the way you want it. If you can create a hot zone of direct heat above blazing burners for searing and a cooler indirect zone to to cook food through without scorching, you know you've got a grill worth its burners.

I started with an empty, closed grill, trying to reach that indirect zone heated to two benchmark temperatures: first 225 degrees Fahrenheit, then 325 degrees Fahrenheit. It was a chilly 40 degrees outside with winds blowing 14 miles per hour—not ideal conditions, but nothing that a well-made grill can't handle.

The Genesis II line offers grills with two, three, four, and six burners. I tested one of the three-burner models, which made for an odd two-zone grilling experiment: I had to choose if I wanted the heat coming from one or two burners, taking up one- or two-thirds of the grill.

Using only the left burner, I tried coaxing the unlit right two-thirds up to a consistent 225 degrees, after letting the grill preheat for 15 minutes. I had centered a temperature probe on the indirect side, allowing me to keep the lid down for consistency in testing.

Try as I might, I couldn’t get the temperature to stabilize. Full-blast was too much; if I backed off, the temperature quickly dipped. I spent 25 minutes fussing with the burner knob every few minutes, at which point I gave up, feeling like I was driving a boat that just didn't have the power to sail upwind.

Next, I lit the center burner for backup. I found a sweet spot after a few minutes with half power on the left burner and a trickle in the center, which seemed acceptable considering the wind. I nudged up the heat, trying to get up to a steady 325 degrees on the indirect side, but it needed constant adjustment to get anywhere close to consistent temperature. With two of three burners going on a windy (but not that windy) day, this is a big flop.

A few days later, when it was warmer and less breezy, I tried again. It took took 20 minutes post preheat, but I finally hit my 225 degree benchmark using just the left burner. More than that, though, was too much to ask of just one burner. Two burners could reach higher temps quickly, leaving just a third of the grill available for indirect grilling. On the grill grate of the three-burner model I tested, which is just over 500 square inches, that's probably enough space to cook for a family of four, but not much more than that.

A Searing Disappointment

The other gas-grilling weak spot I hoped this Weber could overcome is obtaining a good, hard sear. I picked up a ribeye and let the grill preheat for 15 minutes, which left the heat deflectors glowing orange. I patted the steak dry, salted and peppered it, then set it on the grill and let it rip for five minutes on a dial setting Weber calls High+, the LX line's version of going to 11. It came out pleasingly caramelized yet not overdone in the center. Decent for a gas grill, but still nothing exceptional.

Grill companies are starting to get the hang of better searing capabilities, even adding little "sear burners" for the task. Weber’s leaning in that general direction with High+, but the burners are almost six inches from the top of the grill grate, which is simply too far away to get a hard sear. I could get a better, more even sear in my cast-iron pan sitting on the grill’s side burner.

I’d discover in later tests that while the conduction heat–—where the food is in direct contact with the grill grate—–tended to be quite good, it wasn't enough to make it into the spaces between the grates for effective browning. Only by hopscotching the food around the grill grate could I come up with something close to an even sear. This grill's burners go to 11, but that’s still not high enough.

Overall, the Genesis II LX is well-built, comes with a great warranty, and will doubtlessly last a long time. But I’d happily trade many of the bells and whistles of the LX line for a grill that can give me a blistering sear and enough power to keep the indirect cooking temps dependable.

With those weaknesses and—–have a seat—–the $1,400 price tag on the three-burner model, I just can’t recommend it. Results might vary slightly between the two-, four-, or six-burner models, but even still, it's just too much money to spend on something so surprisingly underpowered.

Food writer Joe Ray (@joe_diner) is a Lowell Thomas Travel Journalist of The Year, a restaurant critic, and author of “Sea and Smoke” with chef Blaine Wetzel.