[jcl]

I've played with one of these as well, and I've noticed that while typing raw text is considerably easier, I'm frustrated by the limited support for modifier keys. The control, alt, and Windows keys are put under the thumbs, which I found awkward to type. Also, they are distributed among four keys, so you can't have them all on both the left and right. You thus can't follow the recommended typing practice of pressing a modifier key with the opposite hand as the key being modified.

The function keys are also unusually small and difficult to locate by touch (and, given the above, some function key/modifier combinations are quite challenging). The Windows context menu key is gone entirely, which means you have to use shift-F10 instead, if you need it.

[euccastro]

You thus can't follow the recommended typing practice of pressing a modifier key with the opposite hand as the key being modified.

One of the reasons for that practice is that modifier keys are typically pressed with your pinkie. You also use that finger for typing characters, so for these characters you need to break your habits. Eventually you build new ones, but it'd be better not to need this. Even for characters that you don't type with your pinkie, you may need to stretch your fingers in awkward ways.

Thumbs are only used for the space bar, which is seldom used with modifier keys --and you can use either thumb for it, so you can alternate. Also, thumbs are less 'coupled' with the other fingers.

I'd still prefer my modifiers duplicated on either side, but I can see how this may matter less if they go under your thumbs.

[aikiai]

I was looking to get my thumb more involved in the action, which is what led me to the Kinesis Advantage. After seeing the built in Dvorak support and the natural contour, I was sold. 6 months in, I love it, and am considering buying a second for my home setup.

I remapped a LOT of the keys however. Caps -> Ctrl is crucial, put escape on an elevated thumb button... all the navigation keys to the "4th row"... basically I sat down and thought about where i wanted my control keys to be for easy access, and remapped them there. That solved all of my initial control key problems.

If you're the kind of person who's interested in learning Dvorak, and shelling out $200 for a keyboard, that's not much of a stretch.