So I've heard great things about NetBeans - especially that it is now doing Ruby (as I hear on the JavaPosse podcast). I'll give it a try.
Plus: the Maven integration is way ahead of Eclipse.
Con: after doing a Maven build, the errors don't seem to get updated in the editors - i.e. the editor and the project still show errors even though the Maven build went fine (internal or external)
Con: the cursor disappears regularly - the IDE isn't hung; the mouse still works; just no keystrokes. After restarting NB, it works fine... for a while. (I'm on Mac OSX 10.4.10)
I used to be an IntelliJ user - it was fantastic. Let me go see if I can still get the EAP version for free... Wait - what's this in the comments? Artifactory... cool!