I've carried a gripped 7D, gripped 5DII, or 1D X, much of the time with a big white zoom (28-300L, 100-400L, or 70-200/2.8L IS II) from a BR strap for two years. The only sign of stress/wear is the leading edge of the nylon strap has become a little frayed. I doubted that would affect the integrity of the strap, but to be certain, I emailed BR support. They agreed that there was no danger, but they sent me a new RS-4 for free, anyway.
I've got the Lowepro Toploader Pro 65AW and 75AW. They're great for transporting the camera, plus I can strap a Lens Case to the side for an extra lens, and with the 75AW, either the 40/2.8 pancake or a 430EX II can fit in the side pocket.
So, when would I choose the BR over the Toploader? Any time I actually want to *use* the camera. With the BR strap, lifting the camera to my eye is very fast. If it's stuck in the Toploader, you'll miss shots. I do sometimes sling a Toploader hanging on my left side with a second lens, and the BR with the camera hanging on the right.