I use Eclipse (now that I no longer have an IntelliJ license) for doing heavy-duty Java, but if I can get away with it, I prefer to do things in MacVim. Eclipse is just too clunky feeling when I want to do simple text editing tasks; it totally throws me out of my flow. That's why I'm on HN right now, as a matter of fact. So clearly, I am not an unbiased observer. That said: have you tried Pathogen/Vundle? Vim plugin management these days is light-years better than the equivalent Eclipse nightmare (I've given up on about half my Eclipse plugins as things constantly break).
Proportional font support for code and javadoc, to make better use of screen pixels.
Javadoc on mouse over
When debugging step by step, variable inspection on mouseover at source code point.
Most popular plugin features are well packaged for no hassle installation.
These are few of my favorite things that I can't do in emacs/vim...