We have both. The steam deck has better graphics but the difference is negligible. Most games I’ve tried map the steam deck controls automatically, and with the exception of quake saves move from pc to deck easily.

Clearly the Nintendo is better for the games that are exclusive to its platform. The steam deck doesn’t have the anticheat for some games.

My initial deck had a battery issue (about 10 minutes of life) but support walked me through a bunch of things and they replaced it. 2nd times a charm. The deck can boot into a Linux desktop which is kinda fun.

There is a gog and epic game store proton game launcher I use on my Linux pc I should try… but that’s for another day..