I plan on riding the TransAmerica Bike Race (TABR) in 2018 and purchased these for cold weather and any days with all day rain. They have been great at temps in the low 30s without shoe covers for an hour. I am hoping they will be great at lower temps with shoe covers. I got these because other TABR racers highly recommend them.
These arent quite warm enough to replace shoe covers on cold days, but on the marginal days they provide enough warmth to leave the shoe covers at home. I have not tested the waterproof aspect, but take some comfort that they will help if things get wet.
Bulky, they fit in my cycling shoes, but just barely. Less expensive than competing products.
For gravel adventures I like this sock. Perfect for crossing streams where you might get your feet wet. However, they are a pain to launder, so I only break them out on those special occasions. Also, be sure your tights are the outside of the sock cuff. If the socks are the outer layer all the water that sheds down your leg will slip inside the sock and pool there, it makes for a miserable experience.
I haven't used these that much yet. However, I just did a damp cyclocross race yesterday and these kept my feet warm and dry for the event. The temps were low 40s and it had rained overnight. I am glad these held up especially since I have a problem with cold feet.