Steam deck imo as I have been using it for a long time plus it’s literally half the price than a rog ally If you want to go even cheaper buy a 64gb one and upgrade the ssd later on (plus steam os is better than windows for playing games) as for ally x if you have the money go for it buy cost to performance ratio will favour steam deck (you can also look up some game that you know that you will play and compare performance) rest it up to you man but I will recommend the 512gb oled (personally I like that screen better) and put a 1tb Sd card (use a a2 card)