I had held back upgrading to Ubuntu 8.04 because of reports of
bugginess and the fact that I use a laptop (T60) where I had some
problems on 7.10 getting wifi to work and some kinks with video card
(afaict I can't run compiz).
Anyway I upgraded a few days ago. So far it's been great. It's
definitely feels faster to me and the font rendering is better. All my
settings came through fine and no problems with wifi or video (still no
compiz). The one thing I haven't tried yet is VMware, which i'll get
around to this weekend.
The only problem I have is one I already had - Gnome/GDM won't start
normally, probably due to a borked attempt to install emacs with
anti-aliasing last week.