Overall getting used to Ubuntu was not that difficult, missing software was so far easily installed (though I was not always sure where, but it works). On the average, working with it feels faster than with WinXP, though at times the CPU seems to be used at 100% by a run-away process.
How can I get a listing with how much load the processes are causing?.
On the annoying side, since I installed Ubuntu (3 weeks ago), Firefox crashed more often than Opera on my windows box in the last 3 years.

Also the media player was locking the screen every once in a while, not even being able to change to another terminal. Always had to restart the system. And usually after waking up from hibernation, my network configuration is set back to some default. Always have to change it to connect again.
Well and now the GUI is not loading correctly... trying for 2 hours already to solve the problem - annoyed, not having access to my files including the important documents.
My resume at the moment: several small problems with Ubuntu that I could fix, faster than Windows but apparently more unstable.
Quo vadis?