I recently resurrected a box that's been offline for 438 days (according to the fsck notice when it booted). It took three days of downloading over crappy DSL and babysitting all the config warnings and checkboxes to finally finish a dist-upgrade to Gnome's latest and greatest.
Mas was I pissed. My whole desktop is gone. My background disappeared and the applet to reset it won't work. All the system monitors I had in the panel are missing and won't re-install. There is only one of each type of applet, not the multiple options I used to have. The whole Debian menu is now missing. The keyboard doesn't repeat any more and the keybindings are changed. The font in gnome-terminal has changed. The alt-tab behavior is changed. The window focus behavior is changed.
On my other box, I either reset or learned to live with one minor annoyance at a time as Gnome "simplified" and selected "sane defaults" for me. But to see everything I've lost all at once really pisses me off. If I'm going to have to spend the next two days fucking with it to try to get it back to what I wanted, I might as well try KDE.
<flame on>