I’ve been using Dvorak for years and I looooove it. When people find out (usually by failing to type on my keyboard), they often ask me why I switched.
Here’s a good list of pros and cons. I was convinced when I read this
Comfort: Dvorak wins this contest hands down. The Dvorak keymap is carefully adapted to the English language. For example, most typing in Dvorak takes place on the home row, so your fingers and hands don’t have to move around so much. Dvorak also divides words more evenly between hands, so one hand isn’t typing whole words like agree, fact, grass, greater, opinion, regard…
Lately I’m convinced that I have RSI in my left pinky(could be psychosomatic, like that time I thought I had west nile). I never trained myself to use the shift key on my right hand, so the burden falls on my poor left pinky. I also use it a lot when coding (that darn ;. It’s in the z location if you’re a qwerty user). I mentioned it to Dennis and he found Ukelele a keyboard layout editor for mac. It’s a great program and very easy to use.
This is my new layout:

I switched the ; key with the ‘. I figured reaching up for the ; is better than reaching down. I’ve been using the layout for about a week now and I’ve noticed a few problems with it. I still have not acclimated to the change, so I am constantly typing the wrong character (certainly not helping my attempt to use my left pinky less). I’ve also found that I use apostrophe all the time in regular typing.
Another big problem is that flex builder seems to be the only program that doesn’t entirely obey the new layout. I use lots of keyboard shortcuts (who doesn’t?) and the command key doesn’t map properly in flex. When I hold down the command, the layout turns to qwerty which ONLY happens in flex. I’ve tested it out with every other program I use regularly and it works just fine. Ukelele shows me that when I hold down command I get the dvorak keyboard. What gives? I hate eclipse.
I ended up individually remapping keys in flex. It sucked. I use flex because it’s there and it works. I’d much prefer jedit with the emacs plugin, but jedit doesn’t have as3 autocompletion. (kay I’m sorry if that previous sentence only made sense to me, and a tiny subset of other people)
Overall I’m not completely satisfied with the new placing of the ;, but I’m having a hard time figuring out where it should go. I’ll have to try a few more things to find out what is optimal.