About 4 years ago, I switched from KDE/Kubuntu to OSX. Not because I hated KDE, but because my job needed OSX. It takes divvy, sizeup, apptivate, bartenderapp to do, what I was able to do with KDE out of box. The dual monitor support in OSX is still not in par with KDE.
I have been using Kubuntu/KDE as my main workstation for last couple of months and I love depth of how much is possible with window environment. I think KDE works pretty well for powerusers as well as beginners and I am excited to see its new update!