I spent quite a bit of time corresponding with Injinji regarding the development of ultra-thin liners and waited rather impatiently. The end product has, after more than a year of torturing these liners, met or exceeded most of my expectations. I wear these liners almost every day with merino/alpaca or cotton/alpaca socks of various weights and have noticed a marked decrease in discomfort from both moisture and hot-spots.
Unlike another reivewer, I haven't had any issues with rapid wear in spite of seriously adverse conditions including immersion and exposure to sand and other abrasive materials. Perhaps that has to do with my footwear or is a function of how often I cycle through both my liners and socks; I always carry at least one change of both liners and socks with me whenever I feel there's a possiblity of encountering wet or very dirty conditions and make a point to change socks (but not always liners) as soon as I can after encountering such situations. (Legacy of the principle of keeping your feet as dry as possible drummed into our heads when I was in The Marines.) And while my liners my be soggy and dirty when I change socks, I've never had any blistering nor even incipient blisters in spite of miles of walking and/or hours of being on my feet after immersion.
They may not be the perfect liners for everyone, but they're as close as I've been able to find to date and provide me with the comfort of wearing "socks with toes" regardless of my expected activity or forecasted weather conditions.
Feels true to size
Bottom Line Yes, I would recommend this to a friend
I got blisters on my toes when wearing these socks, and by the third 20-mile day with a 20-pound pack on the Pacific Crest Trail in southern California, the heel on one sock was completely worn through. Yes, there was a lot of sand, but I was wearing these as liner socks with Thorlos, and was wearing gaiters to keep stuff out of my shoes.
Feels true to size
Bottom Line No, I would not recommend this to a friend