KDE seems surprisingly decent now (I tried Plasma out the other day).
Personally, I'm still using Unity 7 on X11, but as that DE's project is now seemingly dead again, I keep looking for a replacement. This one also looks pretty interesting!
I would really like to find something that handles fractional scaling as efficiently as Unity/Compiz. That, the dash, and (I'm ashamed to admit) wobbly windows are what keep me using it.
I stuck with Unity 7 for a long time, but almost all of it can be replicated with KDE these days (I always liked the a top bar with the Window title and buttons, saves space on laptop screens). I'm surprised you find fractional scaling better on Unity/Compiz though, that was one of the reasons why I switched away (especially using fractional scaling at different levels on multiple displays). I still miss the HUD though.