Yes, it's a very huge pain in the back to get it set up right and get used to it, but it was worth it. I use it (for Clojure and Python) when I can not get modern IDE.
However I checked counterclockwise after a long period of time - and there is almost nothing I miss. Eclipse is not my cup of tea (I'm IDEA user, let the Holy IDE War begin :) ), but more pleasant experience than emacs.
This looks cool too, especially the android/java integration.