Still the finest and finest-looking UI today. Just look at this screenshot of one person's setup from 2017: https://www.reddit.com/r/unixporn/comments/6m9du0/windowmake...
The media control stuff tends to be like 5 audio APIs out of date, and much of it is very tightly coupled to 64x64 images, so they don't work great on a modern high-DPI screen.
It's a great concept-- a little bigger than the tiny 16x16 "tray icons" allows some room to provide more context without having to mouse-over them-- but it cries out for apps made in the 2010s and 2020s.
I tried swapping from FVWM over recently, and had some issues where the Steam window wasn't movable, which sort of stopped the experiment.