I've been on XFCE for well over 15 years, maybe nearly 20.
In the beginning I ran Xubuntu because it was faster than Gnome 2 on my ancient laptop.
Nowadays, I just run it out of habit on top of Arch. I've had my stints on KDE and modern Gnome, but I like how "out of the way" XFCE is.
GSDE looks interesting, but I'm sure it will only appeal to the Elders that have used nextstep and similar UIs.