I have two computers running Ubuntu Fiesty Fox.
Desktop: I just took off Beryl since it tends to get bitchy at Fiesty and I was tired of fixing it. I might try to reinstall it later. Full time about 3 weeks now. At first was a little choppy, but then I realized I had to install my ATI drivers(Which you don't even need to search the internet for. I've only had to look for two drivers so far. My MoBo one(for my optical), but that ended up installing itself, and one for a remote(That driver doesn't exist specifically for it, yet), and thats it.)
Laptop: Been running Ubuntu full time on it for 7 months now, haven't even touched XP on it in that long.

It takes me about 2 minutes from clicking restart, to closing all programs, closing the OS, restarting, loading log in screen, logging in and opening all of my settings and programs.
Thats if I'm slow about putting in my password. Very quick. Constantly getting new updates since its Open-Source.

Beryl: Its a fun program. Runs very smoothly. Can be a little technical to install, but there are many walkthroughs that make it easy. That guy didn't even show all of the really cool features of it. I like the 3d windows, unfolding the cube, the rain plugin and the window rolltop blind feature.