In the wake of the KDE3->KDE4 transition disaster a few systems stayed on recent Evergreen versions still supporting KDE3, while my professional systems moved to KDE4 when it became stable and usable again around 4.5.
<snip> Having done a Grand Tour through all current Linux desktops, I was devastated: Only 2 really useful, flexible, and powerful options remained -- XFCE and Trinity TDE. I'm strongly in favor of dual-source concepts, so I will support the survival of TDE, and hopefully its rise to an official "distro desktop" ...
I was on Debian but I also went through a similar path in the past. KDE 3.5 was great, KDE4 was not even worth being called a DE when it was first released (although around 4.6 or 4.7 it was again usable), switched to Gnome 2 until the even more disastrous Gnome 2->Gnome 3 transition. Then XFCE for a couple of years but I always felt somehow limited by its small footprint (but I consider it a great DE). Then by chance I discovered TDE and never looked back anymore :-)
Cheers Michele