M390 steel is tough and is best sharpened with diamond stones. Holds an edge well once done, but can chip. I have a few types of stones for sharpening different knives and woodworking tools. My wife immediately notices when I've sharpened the kitchen knives.
It was funny how I acquired the set. I was over my sisters house fixing a few things, and she yelled to her husband to get rid of the set. I asked why, it was an expensive set. She said they didn't cut well and had bought a new set. She is a bit spoiled.
I have a couple of devices to hold angles, but I enjoy sharpening things by hand.
