These are basically good, thick, cushioned socks. I ordered small, as I always do in socks (I wear a woman’s 6 to 6-1/2). They were perfect until I washed them. They are now somewhat constricting on my toes, even after stretching them before wearing.

Long-time Thorlo sock wearer [use the Hiker KX version most days] owning over two dozen pairs of varying weight and material composition Thorlo socks. This weight work well for me on days I want/need a thin sock with some stretch as these have 7% Spandex.

My last few pairs of Thorlo's show higher quality control than socks from 2012 when I got two pair with untrimmed threads and poor stitching, so I'm giving this pair five stars for good fit design, quality control and constriction.
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Update: 26 april 2015
I'm liking these socks especially for in-house use with slippers, so bought four more pairs of Thorlo's, two black and two grey color. My rating remains at five stars, fit is good and quality control remains high.

Konrad.

For years I have just bought the cheapest athletic socks - 6-pair bulk packs of name brand socks at Walmarts or Sam's Club in generic 10-12 size fits all. They wear out pretty fast, and they do not provide the support and cushioning that I now know can be provided by quality socks such as these Thorlos. They also don't fit my size 13-14 feet all that well, binding on my toes and offering little benefit other than covering my feet in the shoes. I no longer run to preserve what's left of my knee joints, hips and ankles - but I do walk daily. My walks average 2.5 - 3 miles a day, and I keep a very brisk pace - up hill and down - just short of breaking into a trot. it is a work out, not a stroll. At the end of the day, I would still have some joint aches, foot fatigue and swelling. On a browsing expedition around the Amazon site, I found socks listed in my foot size... 13-15. I ordered a pair of Thorlo Lt Hiking Crew socks to try them out. I did so and the result was that I ordered four more pairs. I also ordered a pair of the Thorlo Ultra-lite Hiking Crew socks to try out with the idea they might be more comfortable in warm to hot temps and for more every-day activities as opposed to high intensity fitness based walking.

The Thorlo Lt hikers socks are durable - well made, and offer cushioning for the pad of the foot and the heel. They fit perfectly, with no folds or lose material. The tubular section that covers the arch and instep of the foot is constrictive - supportive and snug, giving an overall feel of comfort to the foot. Now, when I complete my daily walks my feet do not feel tired - they do not have that nagging fatigued strained sense from before. My joints - knees, ankles, hips - do not complain as they did BT (Before Thorlo) -- and at the end of the day, my feet are not swollen.

The Ultra-Lite Hikers do not have the same cushioning effect on the heel and foot pad. That said they are otherwise the same, except for feeling thinner and lighter on the foot. I think they are excellent for the purposes I imagined - but due to their lighter nature (they are after all billed as Ultra-Lite!!) I find that the above mentioned Light Hikers are more to my liking... that is the only reason I give the Ultra-Lites four stars instead of five.

These socks are expensive -- they are worth it. I'll replace them when they wear out. I suspect they will last at least as long as the bulk discount store socks I used to wear regularly. I'm good with that.

these socks are so well made. they keep their shape wash after wash. they hold up. they feel great all day.

I rarely give a sock a 5 star rating- I will pay for expensive socks like these that deliver such quality. Im just glad someone
bothers to make a sock with this level of quality. I'll go through 5 cheap pairs of socks in the time these socks last. And really,
I have yet to wear out a pair of these socks- I bought 5 pair, and i wear them daily for the last year and a half. Im at a job where I am on my feet 12-14 hours a day. These particular ones are great for winter time. I have other thorlo thin ones for summer.

These are nice, but they do run just a tad large. I have to pull them around to get excess wrinkles out from the bottoms after my running shoes are on. The cushioning is not thin, it is medium and fantastic for my nerve damage. I can walk and run in these, much farther than in just regular socks, without pain. I think they will shrink down around my foot better as they get more washings and dryings.