When the first ergonomic keyboards came out, I did not get it. I learned to type on an actual typewriter, albeit electric. In high school I would spend several hours typing a day. We never really worried about carpel tunnel.
When I started using a computer keyboard I had no problem, and again I could spend many hours a day without any problems. I have actually had more problems with my mouse than with the keyboard.
Then, one day, I saw an ad for a cheapy ergonomic keyboard. Reading all the literature at the time I figured I would give one a whirl. Worst case scenario, I'm out $50. Best case - I save my self a lot of pain and maybe surgery.
The switch was weird, one of those split keyboards angled to allow for a 'more natural' alignment of the hands. Mine even had the little feet at the top AND bottom so I could put the high end of the keyboard closer to my body. After getting used to it though, it was not that I noticed a huge benefit in my wrists but in my shoulders. The reverse tilt though is what I noticed first that seemed to help the most.
Unfortunately I dumped tea into that keyboard. I went out and got another, even picked one up for work out of my own pocket. Never did find one of the reverse angle keyboard again, but even just the split keyboard left me feeling, relaxed I guess, at the end of the day.
I have been without an ergonomic keyboard at work for a couple of months. I broke yet another hard drive, so the IT powers that be decided it was time to get me a new computer. Unfortunately the new computer only has USB ports. My old keyboard was PS2. Since the keyboard was a big harry looking it was decided that I should get a new one. It finally came in today - Murphy LOVES the holiday season.
The keyboard is huge, which I LOVE! I do not have huge hands, but big enough that some keyboards are a problem. The keys are responsive but not too clicky. Lots of bonus keys to pull up the web, mail, adjust volume, pause Windows Media Player, etc. It even has a piece to do the reverse angle that I loved in my first ergo-keyboard.
Downsides? If you looked at the picture the keys have a that wave configuration of modern keyboards. I am not used to that. The mouse that comes with it is VERY sensitive and may need an adjustment. There is an extra button on the side that I may need to disable. I use my mouse left handed and the button is not in a good location. The only thing that I can't change about the mouse that I would like to is the wheel. The wheel is nice and smooth, but I am used to something that has clicks, for lack of a better word. Since I have used it for all of 15 minutes though, I will wait to pass judgement on it :).