I have the GPD Pocket 2, and I have no issues whatsoever with the keyboard except that I got some dirt spots from the keyboard on the screen easily (via each key's 4 edge points). Like, worse than my MBP 2015's.
The infrared mouse works OK (I'd prefer the thinkpoint-esque knob of the original GPD Pocket), but you can also attach a Apple Magic Trackpad 2 on it. These work very well if you run a new Linux kernel and patch up some software such as Xinput.
I run Kali Linux on it (its part of my pentest equipment; don't use it for e-mail and such [1]). Slapped an Apple logo on it for the fun of it.
Can I recommend the device? Well yes and no.
Its an OK build quality, and if you apply thermal pads and some copper you can easily run the machine without the fan on all the cores. It does get a bit more hot on the bottom then.
Its a bit expensive now, I'd say, compared to say the current Raspberry Pi 4 plus a powerbank plus a monitor. Its just 2018 price and hardware. Perhaps look at the successor(s) such as the black version or perhaps the Max?
Worst part is they screwed me over cause there's a clear spot on the top right due to attachment of the (touch)screen and in certain light / colors it is rather apparent. CS said they couldn't notice the issue. No warranty was provided. And even then I read about some people had to pay import tax once more receiving their (repaired/new) device but they want you to send the device without value (which means you could lose the whole thing if it gets lost). Typically Chinese.
[1] You could argue you shouldn't use such Chinese hardware for pentest purposes which is a fair point.
but that's the first model. current models are supposed to have much better keyboards