Just received a new Benro B-1 Ballhead today. Spend about 2 hrs with it so far. Thought I would post my initial impression.
My heaviest setup: 50d + 70-200 f/4 non-IS + 580ex II. Camera mount is a Kirk 50D L bracket.
Tripd: Manfrotto 190XProb. 3 section Al tripod.
Original tripod ball head: Manfrotto 488RC2
New ball head: Benro B-1 ball head, L hex wrench, an extra PU-60 quick release plate. Spec is on Benro web site in English:
Installation is easy. Remove old 488RC2 ball head. Screw on Benro and secured it with the 3 set screws on the 190XPROB from the bottom. Ready to use.
Mount the camera with 50D + Kirk L bracket. Very secured. Arca style quick release feels much more secured than RC2 quick release mounting system. Secured with a turning knob. Takes a little longer than RC2's double lever system but feels more secured.
Ball locking knob is very large and easist adjusted. For some reason, it goes from 5 (release) -12 (lock) instead of 0-12 as indicated on the dial. Friction control knob goes from 0-8(tigher) Both work as expected. Panning knob is very smooth.
With the entire lens+flash+camera on, there is no drooping at all. Positive lock at all time. Not sure about long term, but I will find out in a few more months as I sometimes leaves the tripod in the car in the summer time and I often goes to rather dusty area. (I live in Arizona)
Weight: Benro B-1 is about 0.5-0.75 lighter than 488RC2. I can immediately feel the difference when picking it up. Makes a pretty nice combo for people who wants a light secured tripod with an Arca style quick release without paying for a carbon fiber tripod. 190xprob is 4 lbs. B-1 is 0.75lbs. It's a total of less than 5 lbs. Not bad.
Labeling: Mine says Benro B-1A in the front. Not sure what A is for. Maybe an Asian version. I checked Benro and B&H web site. Benro web site has a white line instead of yellow line on B&H web site. Both say B-1. Mine is a white line like the Benro web site.