This harness keeps large-lensed cameras (full sized SLR’s) tight to your body as you go through rough country. It prevents the camera from swinging wildly in a bag or around your neck.
I also use it when I am expecting to have a camera around my neck for a 10 or 12 hour day. I shoot locations for films. I have used it for about two months, and the reason for its superiority is that it keeps the camera tight to your body and quickly makes your camera accessible. Also comes as a two camera system. Great for long fashion shoots as well, I’m sure.