It's tragic how these free software desktop environments get to be good and then revert to a state which should be called an alpha release. Of course GNOME 2 and KDE 4 had some limitations and disadvantages. A big bold change can help there, but I think the only way to truly improve is to slowly evolve into something better. Even Microsoft can't successfully make sudden big changes.
GNOME 3 has improved in the meantime. I still think the window switching, application launcher and top bar are inefficient and limiting, and it wastes screen space. So, I definitely won't be choosing GNOME 3. MATE reminded me that things have improved since GNOME 2, and I don't want that either.
Cinnamon seems good now. It seems to be a combination of the best of GNOME 2 and GNOME 3. Its web page may be unimpressive, but the software works well and has enough features. It seems significantly faster than KDE, and I'm forced to install a lot less stuff. Losing KDE 4 was annoying at first, but now it seems I'm switching to something even better.