i'd definitely recommend blackrapid (i use the RS4) - great design, n works beautifully together with my canon E2 handstrap.. depending on where/what im shooting, i use one of these two straps.. never had any trouble. comfortable too
so far several of my buddies have already moved to this strap. One of the best, because when slung, the camera points down and will not swing or spin around like the black rapid, carryspeed or sunsniper. And it is the only one with military grade hardware. Just take a look at their metal connectors.