Linus Torvalds has announced today via his Google+ page that he's switched back to using the KDE desktop. He's provided his positive and negative feedback after having previously dumped KDE/GNOME in favour of Xfce.
Here's the post from his Google+ page
I'm trying out KDE after a long absense.
It still looks a bit too cartoony, and the default widget/plasmoid behavior with mouse-over pretty much immediately showing the controls for it annoys the hell of me. You can lock the widgets down and they calm down and act normal, but it's some really odd and distracting default behavior.
But ah, the ability to configure things. And I have wobbly windows again.
I do understand why some gnome people think that KDE may have gone a bit overboard on the configuration ability, though. Because some of the "you can configure everything" things are just odd.
Like being able to rotate those desktop widgets any which way you want. "I wonder what that odd rotation thing on the widget control bar does? Whee - trippy".
As a result, right now my terminal and web browser buttons look like a drunken fratboy has been messing with my desktop. I suspect I'll turn them back to their boring upright position (because that's how I roll - boring), but for now I'm mildly amused by the sheer whimsicality of it all.
The Linux kernel creator hasn't commented though on what motivated him to leave Xfce.