I could never stand the crap-rapid strap system, or any other tripod mounted junk...I use a tripod way too often and switch between a 1Ds3, 1D3, and 1VHS constantly. Even as far as mounting a 4x5 on the fly. I prefer to use the Op-Tech sling system with Arca Swiss plates on the bottom. The op-techs are much more stable than swinging on a 1/4-20 thread - I've ripped out the bottom of a 1DsII with a regular plate, and very little weight. The tripod mount is cast pot metal and is fairly easy to strip. I actually mount a modified Hasselblad Winder CW wrist strap from the right top strap lug to the lower right (under the grip), then add the buckles to that webbing line. Then, I grabbed some Velcro cord wrap (double-sided velcro) around the buckles if I plan on the bodies swinging around a lot.
I've never had one of the buckles fail, even with full loads. I just bandolier the two over my body and hike away. Without the Velcro "secondaries", I can even quickly unbuckle the cameras for tripod usage if I don't want a strap hanging around the tripod. The design behind all the tripod-socket mounted ones is obviously for people who never use a tripod - I know way too many of them. Fine for some applications, but these same people later complain about their landscapes not being sharp...hmmm.