Mr. Toad,
The Carson blades add a solid ton of lift for the same power, and some speed as well (less drag at the higher weight). The net efficiency of the new blade is roughly that of BERP, so the difference between them and the old 1959 NACA 0012 airfoil on the original 61 is stunning.
A plot of power vs hover thrust would show the Growth Black Hawk MRB and S92 to be about 2% better, the BERP/Carson blade in the middle and the old 0012 to be about 5 or 6% less than the BERP/Carson.
Carson designed built and certified that blade by themselves (they hired several key retired Sikorsky engineers and pilots). The US Navy adapted the blade, and asked Sikorsky to test and qualify it (be sure it was safe and that manufacturing was consistent.)