I use it since it is in Sid (not sure how long, a few months i guess).
In the beginnig it was a bit different, but now it is good (the change was not as big as gnome2->3 or kde3->4, but for me it was still unusual).
What bugs me a bit is that there is a delay if i try to open the apps menu when right-clicking on the desktop (strange enough it is only the first time, after that it starts normal).
Drag and drop to create launchers. My kids can finally create a shortcut on the panel without asking me how to do it. Good thing!
Learn a new thing every day

I did not know it, tested it with geany, and boom: there the icon is. Very cool.