Haha, Windows XP x64 was great for me, other than the incompatiblity. My Printer didn't work
Everything else did, even the older things, but the Printer didn't!
I found it was faster though. Can't say I timed a boot up in comparison, but in doing things, I think it was better.
Of course it is based on Windows 2003 Server x64, which is amazing really, if anybody has used it, it is amazing.
I personally like Vista. Longhorn has just grown on us, Vista will too. They couldn't really use Longhorn, they have the change the Codename, and even if they didn't few people would understand the meaning of Longhorn in the first place.
I can't wait for the Beta!