the main problem with vista, is they made so many changes between the last beta and the final release, they screwed themselves. Most of the hardware incompatibilities didn't exist in the beta version, because all of the vendors had working drivers for the beta. Then Microsoft came out with the commercial release, and now all of the sudden none of those drivers worked anymore, leaving the vendors scrambling to come up with working drivers for their hardware. In the meantime, the consumer gets screwed because he or she immediately ran out to buy vista, then installed it only to find half their hardware no longer functioned. The final beta worked great from everyone I talked to that used it. I would wait until vista is a year old before I would install it, give the hardware companies time to catch up. But then I always recommend sticking with the OS that was put on your computer to begin with, since that's the one it was designed to run with.
As far as Linux goes I really don't have much experience with it. I have installed it on a laptop once, but I could not get my Cingular aircard to function so I went back to XP. I was impressed with it otherwise. At the current time, i think XP is the best OS out there for the PC market because it is stable and has the least amount of compatibility issues.