After too many upgrades of Ubuntu, and switching from Gnome to KDE and back, my Ubuntu system became behaving strangely in KDE: authorization issues, frequent crashes, pulseaudio & ardour problems. I decided to give another try to OpenSuse, as Linux makes it easy to switch system without losing too much time reinstalling the useful applications.
It's been only a few days, but I am pleasantly surprised with OpenSuse. It feels more polished than Kubuntu. I could not point out to a specific feature, but so far I have not had to fiddle with any configuration file, everything works well out of the box. Somehow Kubuntu always felt flaky, read to break at any moment, while OpenSuse feels solid. But they should consider changing the default font settings in KDE to take advantage properly of antialiasing and pretty fonts (it's only a few clicks away, but still the default is not the prettiest).