But this is like typing speed. If I could type twice as fast, my productivity isn't going to improve much because my programming bottlenecks are mental. What this does allow you to do is develop a nice rhythm, it can be annoying to go back to the old way, but in the big scheme, it probably doesn't effect your productivity that much.
I think there's an important difference. A great part of a developer time is reading code (even one's own), and navigation is part of it. While typing speed is only relevant to writing code. That makes efficient navigation more important than efficient typing speed. Personally, I never cared much about my typing speed (just enough to move from "pathetic French guy typing with two fingers" to "hey I use a majority of my fingers and don't need to look at the keyboard most of the time"), but I do use emacs navigation heavily.
I agree with what you say, but using an editor with bookmarks and simple find ability - and almost every editor has these - is more than enough for efficient navigation of code. One does not have to spend months using vim/emacs until its use becomes muscle memory, to efficiently browse code.
A simple feature of almost all programming editors, having two files open side by side, vastly reduces the amount of short term mental juggling you need to do.
