The other day I sold my Ally after getting my hands on the OLED deck. I think I can only answer your bios question though. I had my Ally from launch and through each bios update up to the most recent 334 I never had an issue or problem that warranted reinstalling Windows or rolling back the bios version. Speaking purely from my experience, I still don’t understand users who claim navigation of Windows 11 is so horrendous without track pads. Using the touch screen or the analog sticks along with the right bumper and right trigger as your mouse buttons it felt fluid and very easy to use, but YMMV. Overall it comes down to battery life for me, but I mostly play indie and smaller games on a handheld so I wasn’t the target audience for the Ally to begin with. Good luck on your purchase and search, regardless of what direction you go, most importantly have fun!
Sad to say it’s a small abyss of a pixel, It’s currently black. I maintain some semblance of hope that it will one day wake up, not likely though.