I gave these as a gift and this is what the recipient had to say:

I’ve been a fan of darn tough socks for nearing a decade. They have always been well made, durable, and comfortable. Simple enough that they can keep the price reasonable. I appreciate that they standby their products to the point they will replace any worn out socks for free.

Truth be told I can’t say I’ve sent back more than 2 pair over the years. Some that I own have seen several hundred days skiing.
I even wear them all winter off the slopes as well.

Their name is a true reflection of the product. Not something you see all the time.

These socks are super comfortable. They are the perfect weight for most days on the slopes. The bonus is they are made in the USA.

Can't beat Darn Tough ski socks. They're comfortable, fit great, and actually last forever.

If you've never owned a pair of Darn Tough socks, you're missing out. They are extremely comfortable, durable, and great quality. The ultra-thin light ski sock means added comfort and extra room in your boot. The American flag design just means super cool looks!

I made the switch to Ultra Thin socks this season and have loved the little bit of extra room in the boot. It may seem counterintuitive but I find it keeps my feet even warmer than the medium cushions I was using in the past. These socks hold their shape through the day, keeping my feet comfortable and skiing hard!

How can you complain when a company is going to replace your socks when you get a hole in them! Not to mention they are pretty comfy.

Darn. Tough. Merino. Great socks that really are darn tough and they do not sacrifice the comfort either. They come with a lifetime warranty that the will back up

Got these for a gift, here is their input:

What else can you say about a quality merino sock that is made in good old Vermont! Sizing is true but will be a bit tight the first few days. Not only are these bad boys comfy as heck the stars and stripes add a nice touch of class. Also, these are the perfect thickness for those who prefer thin ski socks (these socks are not too thin but also not too thick). The everyday sock for normal Utah ski conditions. Did I mention the lifetime warranty? So stop reading and go buy 3 pairs!

Ordered size Medium and shoe size is 9.

Darn Tough once again proving to me that they make some of the best socks in the game. Super comfortable right off the bat, may be a bit tight at first but stretch out quick. These are my go to socks no matter what the temperature is. Grab yourself a pair and see what all the hype is about.

Nicest pair of ski socks I own. I don't have a ton but I always grab these if they aren't in the wash. out of the box they were pretty tight and hard to get on but after wearing once they stretched out a bit and fit great. Nice and tight and very comfortable. None of the seams are noticeable when wearing. Its too bad they are always covered by my ski boot. Love the rocking the red white and blue.

Warm enough for resort skiing but they wick well enough for long tours as well. Minimal amount of seams, they hold their shape very well over repeated use and washing. Always great to rock the stars and stripes as well.

High quality, VT-made, comfortable wool ski socks? With a lifetime warranty? 'Murica? What's not to love?

I have slowly converted my sock collection to 100% Darn Tough over the past 5 or so years because they last longer than anything else and I can send them back if they don't. As a Vermonter, I might be a little bit of a homer here, but I recommend that anyone else do the same.

I have 3 pairs of DT ski socks, I average 50-60 days per winter, and 60-70% of that is touring. All of the socks are comfortable, durable, and repel odor very well (as you'd expect any wool sock to do). These socks are understandably expensive, but given how good they are and that DT stands behind the product, it is hard to find a real downside.

For reference, I am a size 9.5 mens and I can fit either M or L, but I prefer the M.