One of the most important things for me while working inside a text editor is... Key Repeat. I have to be able to hold down SPACEBAR for example and it just run across the screen like a wild beast in the wilderness.
Unfortunately Apple doesn't enable this out of the box for us by default. So let's turn it on and let our wild key run free. From a terminal run the following snippet of code.
$ defaults write NSGlobalDomain ApplePressAndHoldEnabled -bool false
With this ran and completed successfully you should be able to hop in your editor of choice and hold any key until your heart is content.