I switched from Qwerty to Dvorak about 13 years ago, and frankly I don't recommend it.  It's not faster, it's only marginally more comfortable, and it's mildly inconvenient.  I still type Dvorak, but only because the hassle of switching back is not worth the possible tiny benefit.<p>The initial slowdown lasts only a few weeks if you work on your typing speed.  When I first learned Dvorak I lost the ability to touch-type Qwerty, but within the first year I retrained myself and was able to switch back and forth (though I'm still not quite full speed on Qwerty).  The only thing I can't do is use Vi keybindings in Qwerty.  They seem to be in a different part of my muscle memory, which has never been retrained.