I've run both. Started with Gnome.
I didn't absolutely love the UI but it wasn't bad.
Installed a bunch of plugins poked it product tweaked it. Made it exactly what I wanted.
One time I tried KDE and found that it was exactly what I was turning gnome into with all the plugins.
Admittedly, I think the Gnome control panels and tools are nicer.
I think I'm going to have to wait for PBS space to cover this one...