I loaded Windows Vista Ultimate about a week ago, and I've been using it a ton on my work laptop (Dell D610). I was on the Vista TAP and did a ton of work and debugging on Vista BDD, which will be supremely cool when it's out, that working with the final OS is interesting. You see all the weird things being phased out, while other things you loved did manage to stay (check out the very custom power management settings). The best part, however, is that the OS is much faster than when it was in beta, and a bit faster than in RC. Also, Sidebar is not annoying nor painfully slow. Another bright spot is that it can suspend and hibernate repeatedly with little issue. Now, for something I didn't think I would say, I like IE7. It's nice, fast, and handles tons of tabs with no hiccups.
One "gotcha" is to make sure to run certain apps as Administrator (right click on it and select "Run as Administrator") when it needs elevated credentials. I tried to use an ISO mounting utility with Vista Ultimate RTM, and I couldn't get it to actually mount the ISO. It would claim to, and read the sectors and other stats, but would never create the drive letter. I might try again later. If you find this blog and know how to make it work, let me know. I will probably put Nero on here anyway and will just use the ISO mounter in that, but it would still be nice for work.