I purchase a used Arca Swiss Monoball, and love it. I think its the B1. I looked into the Chinese ones and came to realization that they are crap made to look good, like a lot of their stuff. I also purchased used but like new, a Graft Mini Studioball, and its smaller but also very nice.
Anyway, before the Arca Swiss, I had been using the Bogen's with the Hex plates. Not very smooth, and movement after locking down the ball. Very glad I got the Arca Swiss, paid about $122 a year or so ago.
Like a lot of things, used but working is better than new but poorly made.