I love it. I bought one for home and one for work. They are very expensive, but less expensive than not being able to work due to joint damage.
As a bonus, I now know how to touch type every symbol on the keyboard, since you don't have to move/contort your fingers much, it's easy to reach them.
The modifier keys (command, alt, etc) plus backspace & delete are all in the middle, along with the space bar and enter key -- that way your pinkies aren't over-worked.