Vista itself it quite good. But DX10 is a bit, crap, but i dont know if thats MS' fault or game developers. When CoH put the DX10 patch in, anyone who could use DX10 got defaulted to it and ended up getting an uglier game which ran like poop (thankfully you can put it back into DX9 but still............). Some games have DX10 features, but i dont see anything different (BioShock for example). Dx10.1 sounds nice as i think i read that if a games run in it, by default it will have 2xAA ? Anyway, imo, DX10 has been a complete disappointment, its brought nothing to gamers but hassle.
Edit - Oh also, i think its awful how MS tried to show how DX10 was better by comparing models in Crysis to Halo 1 models.