I have no real complaint about the durability of the edge. Almost all the time the edge is hardened correctly. What used to happen, and less so today, is the ultra thin edges, particularly at the Maoist uprising period. Since then, both Sher and Kumar make a modified almost convex edge that does not stick in my experience and wears well.
I have a 25" AK by Sanu that is beaut but I'm worried about the very thin edge, the fact the edge wavers, and the very soft tip. Perhaps because the blade can go deep the tip gets bent, I don't know. But I'm going to cut down a tree this spring and see how she holds up. She has passed the beat the stump test.
Bura still makes a thin edge, but not ultra thin, and his edges are tough. Just my experiences.
munk