I have almost exclusively darn tough socks now and have for over 15 years at this point. I do eventually get worn areas in them but I never let them get anywhere near this bad. A small section of padding worn out is enough for DT to replace them for me. My main hobby is backpacking though so they get used hard and often. I would guess they last somewhere around 500 miles per pair for the micro crews. The business socks are also nice but wear out faster.