I have the GPD 1 and it's pretty comfy, but I ended up not playing games on it much. It's too weak to play many N64 games fullspeed, at least with default retroarch settings. Handles SM64 perfect (easiest rom in my standard test), can't keep 60 in Rush 2049 (hardest test rom I use). Dpad is a little mushy but it's apparently fixable if you're willing to do a full disassembly to swap out the rubber mat and d-pad cross with a DS lite.
It's still pretty great if you just want a "laptop" to permanently leave in your bag. I use it for connecting through hotspot when I want a "real" web browser, and for doing minor edits to .cfg files or file management for MP3 players. I would not recommend the GPD Win 2 if it's still $800 or something nuts like that.