The upgrade to RC2 wasn’t as smooth as it could have been. After installation, on the final reboot, my machine blue-screened, rebooted, blue screened. It was a never ending (seemingly) cycle. It wouldn’t let me load Safe Mode because the install hadn’t finished.
Finally I selected “boot with last known good configuration” and it it loaded, and now everything appears to be ok. Subsequent reboots haven’t had a problem.
That was on my desktop machine. My IBM ThinkPad T42P laptop upgraded fine, but it took hours. I assume this is because I only had 11 Gig of free disk space.
More later on my opinions on Vista RC2 after I get time to play with it some.