So I've been using the final version of Windows Vista for 6 days now, there's one trend that really strikes me using this version.
Check out the Reliability and Performance Monitor:

Straight 10s, with previous builds on this computer this would often dip down somewhat as various applications crashed. So it's a good indication that the system is indeed solid as a rock. Before there would always be one application that would sometimes fail, usually COM Surrogate which appeared to have issues with an XviD codec I was using. Not anymore.
Vista really is solid as a rock, however, my reliability index on my laptop has dipped below a 4, which is my fault for running insanely unstable software. That aside, it is better than XP in so many ways, that I actually got rid of XP on my desktop machine completely because it was sluggishly slow. It takes like 20 seconds to 1 minute for it to load the login screen in XP, and in Vista, it takes only 5 seconds! I also set up my "Zdaemon" servers under Vista, (Zdaemon is Old-School doom), and I haven't had a problem yet. I'm installing Quake 4 and can't wait to see it perform.