I've done a lot, but I really shouldn't have. So in the last few years, I've toned down the number of macros, custom key mappings, custom toolbars, etc. For the most part, I'm of the opinion that developers should get used to the default behavior and appearance of their IDE. Then when you need to work on your colleague's machine, you still know how to get around and manage to help them out. Not to mention that a whole slew of customizations will get broken or rearranged or otherwise reset when an update comes out.
That said, there are a few things that I still do every time I set up an IDE to work on... for example, setting the number of concurrent builds in Visual Studio to be 1, because that feature is so broken that nothing will compile correctly with any greater setting. Apart from that, being an ace with the default behavior will ultimately make you more efficient than spending hours tweaking the software to make it just a little more fluid.