I hiked Half Dome in these socks (2 pairs of MD x Fitsok Merino Hiker and 1 pair Darn Tough Hiker) on Sunday (6/4/17). I wear men's size 9 shoes and I got these socks in M. They stretch to fit me perfectly. Only a small blister on my right foot on the ball area by my big toe, but that's not bad at all with all things considered (17+ miles; 500ish stairs; 4,800 ft of elevation gain). I think my shoes and socks getting wet from walking through the rain storm that is the Mist Trail below Vernal Fall right now likely contributed to the blister more than my own sweat. These socks are seriously great.
DannyMilksThere was no snow on the trail itself, but there was some snow in the area before ascending the subdome. There was also some snow at the summit of HD. I'm glad my feet survived too. It took us just over 14.5 hours roundtrip (including time spent at the summit). And thank you for bringing us awesome products like these socks.
TherocDitto, I sized to shoe size 8 and they stretch to a perfect fit. I'd like to add I was in the last drop and have been using my socks for running local trails and the gym. These socks are champs. They are very comfortable but they're also thick enough that they provide enough cushion. No blisters here. These are the first pair of Merinos I've owned and I am seriously impressed by how they resist moister.