Since the three days of pain in going quad, I've rather enjoyed using Vista x64 thus far. UAC hasn't been as much of a pain as it might and HP even had drivers for my old Deskjet. But beyond my initial impressions, there are definitely a few more 64bit switch issues that aren't going to go away.
There's no flash player plug-in for any 64 bit browser. And no sign of Adobe writing one soon either. YouTube is now but a copy hyperlink, open IE x86, paste and watch away. Joy. At least SlickRun makes this slightly...