For people who type a lot, like transcriptionists, it's great. It takes a little getting used to, but it is [supposedly] a lot easier on your wrists. I've heard from a ton of clients that they love their ms natural. They say their typing speed went up, and wrist pain went down.
Myself, I hate the things. It's just awkward to me, but I've been using the same type of keyboard since the pc junior (you ought to remember that on DD).
__________________
|