I'd been using the sling strap from OP/TECH and it had been working well for me. Well, at least until I took off the grip from my Canon body since the extra weight was getting bit too much for my left hand/wrist (tendonitis). Without the grip and second point of attachment, the camera hang from the sling strap at an odd angle, constantly bumping off the side of my body (even moving the mode dial on one occasion). So now, I've got a strap that I can't really use unless I put the grip back on (won't be happening). I guess I'll be splurging for a BlackRapid in the near future.