After the GNOME 1 to 2 transition, GNOME was too huge and too slow for my machine, so I switched to XFCE (3?). After a while, GNOME developers did an amazing work and improved performance, memory usage and stability, so I switched back to GNOME. Now GNOME 3 drove me nuts (mainly the depressing dark colours I can't change and the inconsistent look of different dialogues, some dark, some bright), so I switched to XFCE, again. I'm sure, the GNOME developers will fix the issues.
Happy birthday, GNOME! We'll meet again.
(don't know where, don't know when, sorry Vera Lynn)