Buyer's remorse, eh? Don't worry, you aren't alone. There, that make you feel better? I know how many people like to feel like they are part of the group, and if Microsoft released an operating system tomorrow that required users to sacrifice chickens and other farm animals on a daily basis for it to function properly... well there would be a segment of the population that would jump on it, just to have the latest OS bragging rights.
Back to Vista, IT IS well known there is a "Vista-penalty", both when running various 3D benchmarks or just playing around with regular games. Not a specific amount of points mind you, but in 3DMark 2006 the penalty is up to 10%, in 3DMark 2003 it’s up to 15% or more, depending on the GPU of course, and in 3DMark 2001 it can be over 50%. Various OpenGL benchmarks are not exempt.
AddSub, did you take the time to test this yourself with the latest drivers? Or are you just going off what others have said? After all, on my machine, 3dMark03, 05 and 06 all run faster under Vista than XP. (Not by much but I have no performance loss whatsoever.)
Joe