The PhD fit amazingly well and don't shift. I've been wearing SW socks for the past 15 years. I have had probably 20 pairs in many different makes/models. The one downfall that I seem to keep finding with the PhD's is that the heel seems to wear through quicker than my older SW socks. In all fairness, it is probably because I use them so much. Like favorite jeans! Some of mine have no more wool on the heel. Given that, I've found that I tend to buy the Medium to Heavy cushion more often than not to get more usable life out of the socks. If you wash properly (don't use Fabric Softener on them) they'll do amazingly well at keeping odor at bay. They also retain warmth even when your feet are wet, unlike cotton. On my longer backcountry trips I'll usually take 3 pairs with me. One I'm wearing, one is airing out (or drying from a stream cleaning), and one is for a back-up (or for my shivering and grimacing friend with wet and stinky cotton socks who is about to attack me for my socks).
In my book, these qualify as "expensive socks." However, I have now ordered several pair after my first pair. The warmth level is fantastic (thicker than trail running socks but thinner than full ski socks). The sweat factor is zero; I can literally wear these all day, being active, and not feel the need to wash them afterwards (I usually do, but def feel I could not). Last but not at all least, is the elastic in the right places. After much use and many washes, they grab in all the right places to stay where they should. I have purchased several pair of the women's for my wife and she loves them, as well. Highly recommend.
Really love these socks. Have several pair and use them for work and also for any of my outdoor excursions. They are super comfortable and keep your feet really warm and dry. Also they still smell and feel fresh after wearing them for multiple days. I will def buy more of them.
Cannot believe something as simple as socks could make such a difference. I purchaced these socks for a trip to the upper puninsula in michigan during mid winter. They worked great for that and now I find myself wearing them to work.