I used to have a Happy Hacker keyboard and write Java (and other languages) in a customize emacs environment. These days I use a regular mac keyboard (so I can easily transition between my macbook and desktop setups) and run IntelliJ. And I feel like I'm a whole lot faster writing production-quality code. There are definitely a few annoyances when using the IntelliJ emacs key binds, but this is more than compensated by being able to do things like automatically download and jump to referenced packages and having the IDE suggest code improvements ("I've noticed that you could be using the Java 8 lambda syntax here..." / "Do you want to remove these unused imports" / "This value may be undefined"). And now I can't write Java without IntelliJ, and I'm going to fail my next whiteboard interview ;)