I use IdeaVim at my day job and can confirm it's gotten better. There are still some rough edges, especially around handling movements like L, M, and H which don't always go where you expect them to. And some operations like undo don't play well with the vim commands such as undo.

And yes, I completely agree about switching between vim and ideavim for different languages, the experience is very different and the sight differences are very noticeable.