Dvorak is cool, but you don't need typematrix to feel its benefits. I use normal keyboards to type dvorak, all you have to do is to change the keyboard layout.
> I use a Typematrix EZR2030 for over a year
So I did kinda checked it out. :-) It's Much better than your average keyboard, though I agree with hailang about not needing it to enjoy a sane layout. In my experience, a sane layout is the second best thing you can do to improve comfort. The first best thing was touch typing itself (most importantly being able to not look at the keyboard at all), and the third was the actual keyboard. I didn't try advanced keyboards such as the Kinesis Contoured though, so they may be more important than I feel.
Can't touch type yet (I still look at the keyboard constantly) though :/ I'll have to invest some time into re-learning how to type I guess.
[1]http://typematrix.com/