I have run a couple of things. Bioshock Infinite, Skyrim, Deus Ex: HR, and CS:GO. Everything but Deus Ex was running over 60fps most all the time. Deus Ex i think had issues with the dual core since it would run at 80fps most of the time but would occasionally just dip to 30 or 40. Have yet to look at wattage but i think ill have enough headroom for an i5 so this thing will be a little monster if i can pull that off.
Thermals are something i am working on right now. CPU get a little warm(50-60*C) but i have a solution incoming for that. There are no case fans but i am going to be adding a large thin intake fan right above the CPU cooler and ill see where that takes me. If need be ill need to find somewhere to add an exhaust.