I have GSO 4.1 in M390. According to all who are in the know, 20CV is an American made steel that is essentially equivalent to the Bohler M390 with respect to properties. I will tell you that my M390 holds an edge very well, I can thump on it with confidence, and I have no complaints whatsoever with the knife or the steel. I own larger GSOs, but all are in 3V. In January I received a 4.1 in 3V, but I have not performed any objective comparison testing between the two as it still seems to be a deep freeze here. But, given the small nature of these knives, I doubt that I can hurt either one with normal use. If you want to see some crazy use, check out some of Guy's videos,
Edit: I consider batoning with a wooden baton normal use with these knives. Just as hard as you can safely thump on it (without smashing you knife holding hand) with a wooden baton through another piece of wood.