I use vim, because I think that using a minimal IDE (if you can even call it that) practically forces you to keep your code simple, clean, organized, focused, and most of all, comprehensible (at least for yourself (at least for a while)). I believe that, when you start needing the help of a fancy IDE to understand and keep track of your code, it is a clear sign that it is growing out of proportion.
That said, I admit that it is a different matter when it comes to things that are not your doing, then you might need the help of an IDE just to get an idea of what is going on.