As best I understand it, this crown provides both a consistent winding feel even as the power reserve nears full, and it also allows the crown to slip to prevent overwinding and damaging the mechanism. I can certainly attest to the first feature, the winding sensation is the same on the first turn as it is the last. A quick web search indicates the crown is employed on some Patek, Ferdinand Berthoud, and Lange models. Pretty good company here!