I switched to dvorak full time about 4 years ago. I popped all the keys off of an old logitech and arranged them into dvorak at first. I did this during the middle of 3rd year cs.
I decided to switch EVERYTHING, not use qwerty again for at least 2 weeks. So I had to modify my computers, and the ones I used in the labs etc.(everything is easy with linux
) No problems there. The first day was very hard... after that it got easier much faster. Within 2 weeks I was at a very solid pace. Around 2 months or less and I was at the same pace I had been with qwerty. Speed is not different, but there is definitely less moving around on the keyboard for vowels. And I tent to mix vowels up much less in my typing.
I can still touch type on qwerty if I need to, not as fast as I used to be.
Overall I'm happy with the switch, won't go back.