Us 115wpm qwerty guys aren't "reasonably fast" - we're way up there - and to be sure, the only reason I have to improve my speed is because it's a sort of hobby.... it won't help me code better. Being able to type with my left hand faster than my friends can type with both is always fun - as is constructing passwords and other shortcuts that can be done with a single hand in the blink of an eye... but that's all just fun and games.