The b-grip belt holder is a different type of camera carrier. It uses a quick release tripod plate that mounts your camera to a stabilized holster that is worn on a belt. The b-grip is made out of a very sturdy plastic composite that feels rock solid. There is a secondary locking mechanism that makes it all but impossible for the plate to spontaneously release.
You mount the quick release plate to the underside of the camera and then lock it into the belt holder and you are set. There are a few different tripod mounts that the quick release plate fits into. I was not able to test this interface as the plate did not fit into any of my tripod heads.
One unique feature of the B-Grip is in the mounting plate. The plate has three functions:
1 Locking the camera into the carrying plate.
2 A quick release plate for tripod mounting
3 Low profile flat surface camera stand.
There is a fold out section, along the lines of a kickstand, on the release plate of the B-Grip that allows you to set the camera down on a flat surface. This is not just a gimmick function, but something practical. Normally when you are using camera mounts along these lines you are not able to set your camera down on it's bottom. With this little kickstand folded out setting it down is not a problem.
All in all there is nothing wrong or cheap with the B-Grip camera carrier, but it is just not for me. I did not find it comfortable to wear a mounted camera with a battery grip. However it is far more comfortable and secure feeling when it is just the camera itself.
I would recommend this as a carrier if you are shooting with some of the smaller camera bodies. I would also try to find a tripod head that the quick release plate can fit into. That way you are using this carrier to it's full potential.