First impressions are very high.
For fun I weighed both heads and the B-1 is 1.65 pounds and my old Gitzo G1377 with RRS QR is 2.00 pounds. I also like having the tension knob on the inside of the main friction knob. No more accidentally grabbing the wrong knob. Also the capacity goes up from 22 pounds to about 90 pounds. I can see why this head is so highly regarded and the fact that stores can never keep them on the shelves.