I feel you there man. Try unsinstalling unwanted applications, defrag the drive, run CCleaner and cleaning tools, do some research on tweaking Vista to have it a bit faster. At least that could compensate the wait.
I think you would be fine on driver's if you go to xp. Just backup the drivers that on the machine. A lot of drivers for vista where xp drivers which work fine. But i agree with the other's upgrade to 7 the drive store for 7 is huge so you prolly wont have to install any drivers other than maybe the bus driver.