There is absolutly zero difference. Although, I know what you mean, as a lot of computers I've seen, especially laptops, seem to be slow as fuck with Vista. I guess I'm just lucky, or it's my 7900, but Vista runs faster then XP for me, even with everything on. EDIT: Just dug this up... http://www.firingsquad.com/hardware/windows_vista_aero_glass_performance/ If you've got a good card, unless you plain don't like Aero, there's no reason to turn it off, I think.