Longtime Linux/KDE user here. I moved away from KDE 4 a few weeks ago, tried several alternative desktops and decided to stick with xfce.
xfce has the features I need; multiple desktops, good maximise window controls (vertically/horizontally/both), grouping of applications in the panel, etc. It's fast, lightweight, reliable, doesn't have uncessesary gimmicks, looks great.
In short, I'm a happy user
Well done xfce devs.