1) You know about ipega controller? It cost about 20-30 dollar/eurs*sigh*
I think I've just been trollbaited into looking up that thing.
-android instead of windows
-no microSD or (regular) usb
-(obviously) no gamepad or keyboard)
-price point comparable to gpd win / switch
-unlike what's suggested, the gpd win 1 can already play gamecube games at least reasonable
2) Mi6 can run Xenoblade Chronicles that GPD Win cant.
3) Mi6 can run now some ps2 games that on GPD Win you can only dream about them.
Anyway Razer Edge Pro Tablet rules the worl of portable emulation. (but Mi6 is a good variant)