I use ubuntu at work. I have done since 2005 I think.

I have tried every window manager and desktop environment under the sun.
I have tried to like unity.
but its not really good enough for me.
its not that I dont get the metaphor. I like the sidebar on the left, and the swooshy effects, like I have on my mac. its just dreadfully slow.
no, its not drivers. its unity.
when I switched to gnome 3.6 yesterday my workstation came back to life. everything works fast again :)

Ive installed gnome tweak tool and the ‘Mediterranean night’ theme pack and the elegance-colors gnome shell theme.

hopefully it remains usable

update:
it didnt really work out. I tried it for a while, and went back to using windowmaker.
then I tried xfce, with a dock, and it didnt really work either, so now im back to windowmaker again.

though I ned keep the xfce4-appfinder and bound it to a keypress [alt+space, sort of spotlight-like]

I guess I just like windowmaker. it almost feels mac-like. and its very fast. very fast indeed.