Have had the OneXPlayer X1 Pro for a few days now. It has been working great! Gotta get the required "this is nowhere near as powerful as the Z13" part out of the way, but to my understanding, the Ryzen AI 9 HX370 it uses along with its other specs makes it the most powerful handheld currently out. This is actually plural, because the company released three different form factors all using the same hardware:
F1 Pro: A 7" handheld with a 1080P 144hz OLED screen
X1 Pro: An 11" tablet with a 1600P 120hz IPS screen
G1: An 8.8" laptop with a 1600P 144hz IPS screen
Nice that there's something for everyone that way. I'm not sure about the F1 Pro, but the X1 and G1 also have Occulink ports. I might try an eGPU if I keep the X1 Pro.
So yeah, the X1 Pro despite being an 11" tablet counts as a handheld. It's kinda awkward, but you can slide on and attach controllers to either side of it like the Lenovo Legion Go to use it this way. The tablet isn't as heavy as I would have expected, but it's not exactly the lightest thing to hold and probably would get tiring a lot faster than other handhelds. I don't particularly care about using it this way so it's a non-factor to me. You can also purchase a $30 connector to use the controllers more like a traditonal gamepad and connect it via an included USB 2.4ghz dongle. For the price this thing goes for, they really should have included that connector. That said, they do include a case for the controller, a keyboard cover with backlit keys, and although the tablet doesn't have a built-in kickstand, it comes with a magnetic back cover that does that instead. The build quality on the tablet is pretty impressive. I was expecting plastic, but it's made entirely of metal.
Performance-wise, this is like having a Legion Go on steroids. The faster processor/upgraded iGPU/32GB of ram is welcome and there's a noticeable bump in performance compared to the Z1 Extreme handhelds. It's not a massive performance bump, but I'd say everything runs about 20%-30% better depending on the game. You can play a lot of more demanding titles at 1080P/1200P if you're OK with 30 FPS, but I prefer leaving it at 720P/800P to get 60 FPS or better. With upscaling, most games still look like they're running at full HD anyway. The one exception is Call Of Duty Black Ops 6- I play multiplayer a LOT and I was pleasantly surprised to find that I can get 90-115 FPS in multiplayer at 1200P. Dropping it down to 800P does make it go much closer to 120 FPS most of the time, but it's really nice having that game at full HD
for realz.The other nice thing about this versus the Z13 is its size. 11" is far more compact and portable. The power brick is also a lot smaller. I'm able to fit this thing into bags/backpacks that I couldn't put the Z13 or my 14" laptop into.
Would I recommend the F1 Pro/X1 Pro/G1? If you want the best performance currently available in a Windows handheld, then yes. But keep in mind that these are pretty pricey. Like double the cost of some of the other handhelds The cost for the configuration I got was $1600. Definitely a product for the hardcore crowd for sure. Compared to the Z13 though? It's a bargain. Since this also came with a 2TB SSD, the cost versus the Z13 plus an added 2TB SSD for that is $1200-$1300 cheaper.
Barring no issues, this is a keeper. With my luck, I wouldn't be surprised if it gets returned because of fuckery.

But that's why I got this from Amazon. 30-day no-hassle returns!