I got the Black Rapid RS-Sport for Christmas. I don't use the BRAD under-arm attachment much, but it's worth it to have that option. love that it's quite narrow and unobtrusive.

Also means I can easily remove the strap and have a camera that i can whip out of a back quickly without tangling on anything.

Will never put a neck strap on the camera again.

Only possible problem, as mentioned is what to do if you use tripods a lot.