I like to have both on the camera, so when holding in hand I can use the wrist strap and ignore the big strap, but when I need to park the camera temporarily I use the big strap, either on my shoulder, or around my neck when I need more security. Then if I have a small bag for more protection, say, going into an eatery and keeping the food off of the camera, the camera strap can act as the bag strap for ultimate convenience. But that's one camera - if I use a small camera or carry both cameras, I might move things around. Which is why quick-removal straps are very convenient.