I'm still very unimpressed with cinnamon. It seems very sluggish on decent hardware compared to gnome 3.6 or gnome 3.8, although its memory usage is significantly better for some reason.
It still has some very basic polish issues that should have been addressed long ago, such as the window list applet going offscreen with long window titles or too many windows. I still don't like the cinnamon menu at all (but at least they've made it less sluggish to open), it just seems like the most mediocre "start menu" implementation i've ever seen.
They have done a very good job with the nemo file manager though, the UI is very nice and they've restored a lot of removed nautilus features. The new software sources tool is also very nice.