Kicks ass! Got one a few weeks ago, and finally got it on my camera last weekend while I was shooting a cat show. Just a nice way to carry the camera that is comfortable! The video convinced me to buy one, and I was very pleased that it is indeed that awesome of a product.
The only change I made is I use a real tripod mount on the strap instead of the thing that comes with it.
http://blackrapid.com/ just because I can't really describe how it works.
Anybody else have one?