I have the BR-4 model and it is the only model from them I have experience with, it has worked well for me with no issues. I have run it on guns from an 8 pound 1 ounce unbraked 28 Nosler running very stout loads and with horrible recoil, a 300 WM under 9 pounds that also is nasty to shoot, and 12-14 pound rifles with light to moderate recoil. If the light 28 didn't tear it up I don't know what would, over 100 rounds shot as well, just make sure it's tightened down well LOL.
My only regret is not spending up for the QD lever in place of the thumbscrew/nut, sometimes doing load development or shooting several rifles it gets to be a pain switching it back and forth. I bubba'd a QD lever on it and it doesn't work great, I should have bought theirs and been done.
I would buy another one in a heartbeat.