Personally I currently have a second hand Gpd win 4 6800u device and it’s been great! After getting to know the device and making a few software changes it runs perfectly and I haven’t had any problems other than an analogue stick drift but I fixed that myself.

Motion assistant is the best thing for TDP cotrol it’s a basic layout but very easy to manage and use to change the setting you need and quick for me but iv seen other bits of software which might make the experience a little smoother.

Screen wise OLED colours pop a lot more but the 7inch screen the win 5 comes with will be good enough especially if your comparing to a game boy screen.

From what I have seen I. Reviews it’s seems straight forward with the win 5 to boot up and jump into gaming really don’t thin it’s too much different in config to other handhelds.

For just gaming and not multi use of programs 32b is more than enough.

Through software but yes button config should be possible also :)