However, even when editor keyboard commands become "muscle memory", there's still a little part of your brain that has to make a decision regarding how you're going to navigate/select/change/delete from point A to point B. With the mouse, you don't have to think up an algorithm for editing. You just think about the code at hand. I've found that the fraction-of-a-second decision making regarding _how_ to edit can be enough to interrupt my train of thought. Reading this article ( http://www.asktog.com/TOI/toi06KeyboardVMouse1.html ), while it may be quite old, helped me realize this fact.
That being said, I still think Vim is a great editor, and I don't mean to make any blanket statements about it's effectiveness. I just also believe that the obsession with "efficiency" is totally blown up with regards to editing text. Shouldn't we strive for efficiency in translating algorithmic thought to programming language? I think the keyboard crowd (myself included) tends to get caught up in the little details.
My trackball is all of 4 inches from my right hand, and I always know where it is because it doesn't move around. Now, you can try and overplay the difficulty of grabbing the pointer ("I have to instruct my arm muscles to tense and pivot at both the elbow and shoulder while causing my fingers to curl into the appropriate shape" and so on) but I'd wager I could get the cursor to a given semi-distant point on a screen of code faster than even the most frantic of vim key-pounders.