Every so often, Plasma freezes on me or the graphics get cluttered. It is a hassle to restart KDE (logout/login) when you have 101 tabs open in Firefox and several xterm windows.
I had been a Gnome user since shifting to Ubuntu a couple years back, and recently shifted to Kubuntu/KDE when KDE 4.2 was released. Its been mostly stable, except for the occasional Plasma issues. Individual components in Gnome can be easily killed/restarted. For eg Gnome Panel can be killed/restarted using the following command.
killall gnome-panel; gnome-panel &
Now the same can be achived in KDE too. This is how you kill/restart Plasma.
kbuildsycoca4 && kquitapp plasma-desktop && kstart plasma-desktop
The above command can be run either through the terminal or krunner (kde run command).
No more restarting of KDE to clean up plasma mess. 🙂
I upgraded to KDE 4.4 last week and its has been largely stable and amazing to work with. KDE is a much more powerful desktop shell than Gnome and I would recommend KDE 4.4 for everybody who use Gnome just because of a lack of better choice.