I really liked the RS-7 itself, I just didn' like the RS-7/BRAD combo. I had bought BRAD (underarm strap thingie) after using RS-7 for couple of months hoping it works as stated (allow me to bend forward/down a bit without the camera's weight pulling/rotating the entire strap around my body, crashing camera onto the ground). While it actually did work, the implementation was really clumsy and it has too much excess webbing on the underarm strap (I'm assuming to accommodate for wide range of body size).
With RS-Sport 2, the underarm strap is integrated a lot better and works a bit better as well. Also, there's nowhere near as much excess webbing left on the underarm strap.