O rly? Have you actually used it? I tried for months while using RubyMine. The IdeaVIM plugin was one of the reasons I was ultimately driven back to regular vim...the inconsistencies and bugs were pretty bad...to the extent that some things like undo would lose your changes completely (i.e., no redo). I really wanted to like RubyMine/IntelliJ/IdeaVIM, but the bugs were a deal killer. Coupled with the fact that many were known issues and there was no commitment to fix them and my choice to go back to vim was easy.

I should note that the vim support in netbeans and eclipse was just about flawless. It's a shame IntelliJ couldn't steal/adapt one of those projects to work within its IDE set.