It's Ok... But definitely not as good as the premium ballheads (Arca-Swiss,Markins,Acratech,Kirk,Really Right Stuff). I would say that Benro tends to over-rate their max-load specs. I am sure the B-1 cannot take heavy tele primes without having any problems.
I've been using the B-1 for a couple of months now, so far, it's been pretty good for what I do. Mostly it's the 5D2+grip+16-35 and sometimes the 70-200 2.8, so far no issues, and it's rather steady even when tilted at an angle. Definitely not as solid as the markins and those top end make, but good enough for my usage.
Tried the Benro KB ballheads before on 70-200- excellent, not as smooth as a Markins, but it holds the weight well with no creeping and totally stable, for, as u mentioned, several fractions of a Markins price- very well worth it, just like getting a performance of a Lamborghini SV for the price of a Nissan GTR.
Why pay for a Porsche 911 when u pay several times cheaper for a GTR which outguns the real thing?:bsmilie: