Almost everyone I know who's tried Dvorak thinks it's great, and many claim it has changed their life for the better. But your mileage might vary. Here are some factors that might make switching to Dvorak more or less desireable for you.
Some people have had trouble regaining their old speed. This seems to happen if they don't give up QWERTY entirely while they retrain, or if they train too hard.
If you have to type constantly and can't afford to lose a few weeks' work, I
suggest you put off switching until you can take some time off.
Although many people (including myself) achieve much higher speeds in Dvorak, a few have complained that they still can't type much faster after switching, especially fast QWERTY typists (perhaps 60 or more WPM). Even so, they usually find Dvorak more comfortable.
Although Dvorak has alleviated some people's repetitive-stress injury (RSI) symptoms, don't neglect other forms of prevention and treatment. Nothing is a cure-all.
These are some complaints I've come across, but I must say I've done quite a bit of programming and computer swapping since I learned Dvorak, and manage to do all right. The only sure-fire show-stopper I know of is having to use a VDT on a system that doesn't support key mapping.
Back to Introducing the Dvorak Keyboard.
Marcus Brooks -- 5 April 1999