NOTHING is perfect. Having said that if you are not experiencing any grievous problems
with your vista (get those fixed first if possible), read the list of software and
devices that don't work at the following 2 links and go for it. Thinks are much better
if done according to the rules. There are those who will always be naysayers, but
"can't never did anything".
http://support.microsoft.com/kb/948187/http://support.microsoft.com/kb/935796