I may try KDE again, though the last time i tried it, it was a bit "too much"... such HUGE menus were just uncomfortable... For me, it was an overall impression of a bit too much of everything, everywhere.
Now, I can say the only thing I really don't like in XFCE is Thunar... for me it lacks lots of functionality (like, ffs, copy-paste with right button!). But even so, i cant even think of trying to use unity or gnome shell again.
So no, it's not like we have really advanced much. With XFCE sometimes I feel a bit like 1999 again, suffering here and there with stuff that doesn't exactly work as I would like, but also feeling confident and comfortable with it.
Probably KDE will be the desktop of choice for most of the "normal" linux desktop users... until they decide it's time to move to tablet interfaces too!!