I upgraded from Vista Home Basic to Vista Ultimate- first I closed all of my spyware, AV etc and shut down all programs in start up. Upgrade was flawless and I am extremey pleased with Vista Ultimate regardless of all of the negative comments about Vista.

I upgraded my vista premium to ultimate(not enough difference but it was free) it came with a price. My computer didn’t like the initial install and had to revert back to premium. Not to be taunted I tried again. One feature of the upgrade is it will copy your old os files to a packet to be recovered later however I was not happy with performance after the upgrade. NOTE: You need to be careful not to fall asleep when upgrading though it does take some time to do the upgrade the computer will default back to hibernation once the start screens come up to setup the new OS, and mine went into hibernation which has yet to successfully come out of so I had to hard stop in the middle of upgrade. Fragmentation was one of my biggest problems. I finally just wiped my drives of all data and loaded a clean copy of Ultimate. Now I couldn’t be happier. This is all pre SP1 and I have yet to make that leap for fear of having to reinstall again:)
Hope that helps Good luck