Depends on what you want to play. Want to play emulators and pc games that do not require many requirements? Steam. Including all of before, and also want to play most PC games not newer than 5 years ago? Rog
The Steam Deck more performant in the <15 watt range than any other handheld still. If you don't care about power efficiency though then the Ally is better.
you mean the non x rog ally?
that thing is just outright worse outside of the higher resolution screen and 20% bigger battery
in practice you're getting buttfucked by anus and windows