I didn't really believed much in ergonomic keyboards when I first saw them with their weird curves and slopes. Then when I finally bought my first ergonomic keyboard and watched my typing rate plummet I was ready to write them off... until I got better. Better being I got better at typing, while I could type fast previously thanks to a ridiculous amount of time spent in The Typing Of The Dead when I was young I still weren't very good in recognizing which fingers should hit which keys. The slope and space of an ergonomic keyboard forced me to learn to position my fingers properly and thus I was a better typist. And also my wrist felt less stressed after a whole day of typing, it was amazing. So now I'm no longer skeptical of ergonomic keyboards, and I embrace them fully.
And here's my latest keyboard : The Microsoft Sculpt Ergonomic Desktop.