Like I said, if Vista works for you, then good for you. Fact is more times than not anybody who upgrades to Vista is going to have compatability problems. For instance, if you are running an Nvidia card on an Nvidia chipset, poor Vista drivers will render gaming performance much lower than the same system running XP.
My CSS stress test results: 130 fps in XP, 78 fps in Vista.
Aquamark 3: (Yeah I know its old but its still viable in aging systems like mine) 89,000 in XP, 73,000 in Vista
F.E.A.R.: 63 fps in XP, 45 fps in Vista
I can't blame it on myself either, because I did many re-installs of the chipset drivers and video card drivers
Also, will anybody disagree with me that Vista Ultimate Extras are a complete sham? You pay $200 extra and all you get is a stupid poker game and something called "Bitlocker" which most people will never use.
On the Vista Ultimate box it says "stay on the cutting edge with Vista Ultimate Extras" and shows a screenshot of the poker game. Now that's cutting edge enough to warrant $400 for an OS!