About four years ago I began experiencing some of the early symptoms of RSI, so I decided give Dvorak a try as an experiment. My personal experience is that it has increased typing comfort, my RSI symptoms went away, and my typing speed is about the same as before. Some people will pick it up faster than others, in my case it was a couple of months before I felt that the muscle memory had fully developed.

Once in a while when I have to use a QWERTY keyboard, the difference in the amount of finger and hand movement is very apparent. As for typos, I certainly still make them, albeit different ones. Just a guess, but I'm guessing that they are probably similar or the same physical key combinations I had trouble with in qwerty.