I switched from qwerty to dvorak about 10 years ago but I did it for RSI reasons rather than speed. I'm not sure if it was the dvorak that cured the RSI or the fact that the switch made me really slow for about 3 weeks.<p>Also I'm not sure if my speed was vastly increased or not - my dvorak is 75-80wpm on tests, but I didn't test my qwerty beforehand. For the first few months I think I was typing faster but I was also making more mistakes owing to the decreased movement required for each keypress causing letters to come out out-of-order. It took a while to get that under control.<p>One thing that does improve: you realise that remapping individual keys isn't a big deal, which is quite liberating. For example I've moved a bunch of punctuation keys about (e.g. parens) to make programming easier and more comfortable. It takes a couple of days to adapt per key.