Mailing the story:

Am I happier now than I was before Mageia installation? Most likely yes. Mageia proved itself very stable and nicely composed system not only in Live run, but also in full install mode. Yes, I still have something to work on before I can make final decision to dump Kubuntu. But that hour is very close I believe. And even now I have system which works smoother and quicker then Kubuntu, does not have issues with desktop effects and shutdown. These two facts are more than enough.