Nintendo

I bought a KK3Max and it's a really good controller, with a couple of caveats.

It has the best control sticks I've ever used, hands down. Hall effect sensors instead of crappier potentiometers like the official switch pro controller mean no risk of the infamous stick drift. Very responsive, and allow me to raise the stick sensitivity for the most precision (still prefer a mouse for FPS games, but for every other genre it's a good alternative).

The analog triggers are excellent and a physical toggle lets you switch them to digital triggers. Alhough the triggers are spongy in digital mode, with a fair amount of travel time before registering the input, you can open them up and mod them to eliminate this delay. Apparently it was added after product testers complained about the triggers being too sensitive or something (which I wish they didn't).

The buttons are solid, without sticking. D pad is good, though I prefer classic D pads from older Nintendo controllers like the Wii U and the SNES (the switch pro D pad is trash). Back paddles are welcome, though the lower paddles are less ergonomic unless you bend them to rest closer to the back of the controller. You should also note that the back paddles can only be assigned to other controller buttons, and not unique key binds. The gyroscope is also perfect in Switch mode, though I wouldn't recommend it in Xinput mode because it can feel wonky and imprecise. This controller also has a form of HD rumble, and even carries an NFC sensor for Amiibo support.

The big caveat is the input delay when connected by Bluetooth. It can be noticeably slow, even in Switch mode, adding a good 40+ ms of lag. For most games that don't rely on precise inputs, you can eventually adapt, but to resolve this issue for games like Super Smash Bros or racing games, I'd recommend a long Usb C cable for the Switch, or to use the 2.4 GHz adapter on PC.

One more thing I'd note is that this controller doesn't come with proprietary software to customize input mapping. This is a positive for me because I don't care for bloat, but for others that would prefer extra customization options, it's a sore spot.

It's been about a month, and I haven't had issues with quality control or component failure. I'd recommend the controller for people who don't want stick drift, and enjoy a controller that punches above its weight (the Xbox elite 2 controller that rivals most of its features costs more than twice as much). Although its input lag in Bluetooth is a big headache, its performance is exceptional by wire or dongle and it almost completely outperforms the official Switch Pro controller IMO (which still suffers from stick drift and has a terrible d pad).