You'd be hard pressed to break the Mule I think as well. I've misused mine deliberately, throwing it, prying with it, batoning it through wood. The blade is AUS-8, so it isn't super tough, but it seems to be holding up fairly well. Keeping the edge in shape is not a problem, I've only had to touch up the tip a little so far. The grip is really substantial and the lock and joint are VERY strong imho.

I got one because it was popular amongst the seargents on patrol in Baghdad and got good reviews there when I was there. It was a good accompaniment to their primary fixed blade(s) and their Multi-Tools.