I have been running Ubuntu as my main OS since 8.04. I just installed the developer version of 10.04 and have to say there are some nice speed improvements that are noticable. also, some glx errors seem to be better and overall system reaction and operation more stable..
when the stable release is out it is certainly a viable alternative to OSX and Windows7. Both my gf and 75yr old father use it daily and love it. When I was using windows for a week for project they wanted ubuntu back... (my gf runs vista on her laptop btw)
