How is the speed? Last time I tried it, about 6 months ago, there was a very noticeable lag when switching between modes. I ran into the maintainer of IdeaVim at PyCon and he said it should be better but my trial period expired and I never got a chance to try it again.
They just released an update a week ago that was supposed to have fixed the problem. It does seem better, but I haven't used it for long enough to properly verify that.
Hi, in case you're still interested I've had a chance to try it a bit more. Performance is much, much better, especially on a retina display. And they've even fixed the dot command with autocomplete.
It's still not the greatest vim emulator, but it's much more usable now IMO.