So I'm used to keeping my knives sharp. I'd say @ 90% I would at least perform a touch up. I decided to test how long i could go before actually being forced to sharpen. It's been 2 months and I'm surprised to say my edges are mostly at about 80%. No where near what I'm used to, but still completely useable. I think I will take them a little further still; maybe to the point where I feel I have to saw to pierce skin. So, are are we anal and unreasonably wearing our blades to expect to keep an edge at above 90%?