I use a bunch of editing tools. OmniOutliner, TextMate, IntelliJ IDEA, vi, the editor that lives in my email client, etc.
One of the great things about TextMate is that it groks the power of the shell, and of the platform.
This is shown throughout the product, from being able to type a command and have it kick out, run it, and put the results back in the document, to the plugin system.
I have written a bunch of plugins in TextMate to make my life easier. Why haven't I done this in IntellIJ or Eclipse? The thought of doing those is daunting. Time consuming.
With TextMate I can write a plugin in any language that I want because the contract is so loose. It will shell out, and I can run ruby, perl, lisp, or whatever I feel like for the given problem.