Sad to say, I’ve jumped on the Torvalds bandwagon and switched from KDE 4 to GNOME. Sorry to all the hard-working KDE developers, but I just don’t have time to put up with a desktop plagued by numerous regressions, and worse, a crippled front-end to NetworkManager. There appear to be two versions of knetworkmanager – the 3.5.x branch which for some reason went under a significant UI redesign and is now harder to use and more buggy, and the 4.x branch which AFAIK is still unfinished and unreleased. That was the last straw for me – the NM front-end is arguably the most important component of any modern Linux desktop (from the point of view of laptop users anyway), so I find it fairly staggering that KDE still doesn’t have one which is stable, polished, and well-designed with respect to usability.
There were other things, like korganizer getting slower and more buggy, phonon not working right, plasma’s bizarre customisation UI and tendency to leak memory like a sieve, a device notifier pop-up which often makes new devices invisible and unclickable … but enough is enough, life is too short. GNOME does what I need (which isn’t much, thanks to the flexibility of openbox).