I used to love KDE, then they messed it up with KDE 4. Moved to Ubuntu / Gnome. Then Ubuntu screwed it up when they made it all Unity based. Screw that, I was happy working the way I was without to much shiny. Now using XFCE, and its refreshingly simple.
People make a big deal out of tmux's split screens, but my workflow is much more flexible with xmonad and GNU screen (with the caveat that it requires more upfront).
I switched over to XFCE for a while, until finally settling on i3. I'm perfectly happy with i3, and even if KDE pulled their heads out of their butts, I doubt I would go back.