I burn through Darn Tough socks about as fast as I do a regular cotton sock. They are not tough at all and the warranty thing is a PITA. Send them in, wait a month for a code, pick out new socks, wait 2 weeks to get socks.
If I had not invested enough money into them I would just quit buying them/warrantying them, but here I am!
I just sent in 5 pairs about 3 weeks ago and still do not have any reply with a warranty code. The only way to make it work is to have about a dozen pairs and wait for a few to get holes and then send them in together or the shipping will kill you.