I recently moved to using a Cintiq 21UX and also upgraded to Ubuntu Studio 11.10 and am happy that Krita 2.4 works perfectly now! I couldn't use it before because of the issue with X, Qt & Wacom devices under the older 11.04.

I've been testing out 2.4 and it's extremely versatile and *very* stable. I love MyPaint and Gimp Painter, but having the best of both in a single application, plus with better color control, CYMK, etc etc etc... I think Krita is the winner here!

It's great to hear that you're enjoying Krita!