I haven't used any other IDEs really, so it is possible there are even better IDEs, but the step from Emacs to IDEA was huge (but of course it was also a switch from C++ to Java).
Editor-wise it's Emacs and Vim (for the past year or so).
My thought was that any IDE would've made you more productive imho. That's the point of an IDE to give you as much possible so you could focus on your tasks...
True story: Before Intellij, I was working for a client whose IDE standard was VisualCafe. I hated it so much and kept interfering with what I was doing that I actually reverted to Notepad and building/testing via command line.
Editor-wise it's Emacs and Vim (for the past year or so).
What's your experience with IDEs?