Yes! Switched back to KDE (Kubuntu + KDE 4.11 here) a few days ago. I'm really happy. I finally have a mature and stable system again. Unity was just to buggy for me (13.10) but KDE is really fast and stable. I don't want to sound like a shill here. I was happy using KDE 3.5 back in the day and hated all the KDE4 ideas... for anyone wondering if KDE is usable again I think it's the case (maybe it is for a few years longer - I did not bother to look).
However it took me a few hours to configure the system to my needs and adjust the often stupid (IMHO) KDE defaults to sane settings. But I could without problems.
Give KDE a try! XFCE / Xubuntu is to ugly and unflexible for my taste. KDE is also does not hog too much memory - without Semantic Desktop it's only about 400MB RSS (amd64) for the whole system after a clean boot. That still a lot but a little bit less than Unity and a little bit more than XFCE.
I've been a hardcore KDE fan since over a decade. Of late though, I am inclined to move fully to GNOME 3. I use KDE on my laptop and GNOME 3 on the work desktop. I find Gnome 3 much more pleasant to work with and it let's me forget about many details of doing things on the desktop. Once I got used to it, it allows me to switch tasks faster and with less focus/flow loss while doing so. It doesn't have a "minimise" button by default in GNOME 3 and at first this annoyed me but now I see that I never think of the concept of mimising something in my workflow. It's one less thing to think about.
I know there's a lot of hate for GNOME 3 floating around but I have tried it and I love it. I showed it to a lot of colleagues and most of them have switched to it too. I think in the next LTS release of Ubuntu, I'll switch my laptop to GNOME 3.
The GNOME Remix is hobbled by Canonicals decision to stick with older releases of GNOME and GTK. Ubuntu 14.04 will likely ship with GNOME 3.8 instead of 3.12. For various technical reasons they can't just put the newer version in a PPA.
The issue is that Kubuntu's default has a lot to desired compared to OpenSUSE's KDE polish or Arch Linux's vanilla KDE. I always found Kubuntu more work and less "useful."
However it took me a few hours to configure the system to my needs and adjust the often stupid (IMHO) KDE defaults to sane settings. But I could without problems.
Give KDE a try! XFCE / Xubuntu is to ugly and unflexible for my taste. KDE is also does not hog too much memory - without Semantic Desktop it's only about 400MB RSS (amd64) for the whole system after a clean boot. That still a lot but a little bit less than Unity and a little bit more than XFCE.