@AlexBravo: A question about your progress. Did you find that you improved and improved your rate, up to a certain point, and then reached a plateau, a kind of natural carrying capacity of muscle memory? And if so, what is your (presumably natural top-rate) wpm? Or are you constantly improving?
I'm presuming the former - there are limits intrinsic to the form of any input machine, and also to individuals' abilities. When learning to touch-type (which I do all day every day), I gradually improved until I hit about 85-90wpm, and that has been it for years.