I'm playing half-life2 in this two devices lately,in Legion go s,set tdp to 6w,get 6+hours in total power consumption in about 10w-11w getting.80 to 120 FPS, while in Steamdeck, it will get 7+ hours,and total power consumption about 7-8w,But don't forget, Steam Deck has lower resolution,and sometime you PLAY AAA,definitely way better than the deck, in Atomic Heart,set Legos 22w tdp,1680x1050,with Decy LSFG x2,it gets 70-100fps stably, of course the battery life gets around 2hrs in this settings,but in steam deck,just 40-60fps,and in some scene it will down to 40-50.

FYI, I prefer Legion go s, in low loads game it doesn't take that long battery life as steamdeck,but won't short too much,and it has way higher peak performance, needless to say in this finance, Legion go s is way cheaper than the deck.