I've tried Gnome in the past, didn't get it, and moved back to either Mate or Unity. Then I heard that Ubuntu would move to Gnome, and I decided to make an effort. It turned out that the default settings make Gnome into something I really don't like, while it's really customizable into something that resembles Mate close enough. I haven't gone back since.

The Gnome project should add two shortcuts on the desktop with scripts to set Gnome to mimick Mate or Unity, so users get their old desktop back with a few clicks.