These boots (for me) are very comfortable however I find their claims of 200 grams of PrimaLoft to be laughable at best because it seems as if they forgot to insulate the toe box. I hiked Mt Monroe today. It was 15� at the summit. Not particularly cold at all, especially for something that purports to be a mountaineering boot. I couldn't feel my toes. Yes I had a proper sock on, no there were no circulation issues. My Asolo 520 backpacking boots are warmer than these. If you want a comfy boot, with a stiff sole and gat ankle support these are fantastic. If you want to come back from a winter hike with all of your toes, avoid this boot. I really wanted to like these boots because they do fit so well but if they can't keep my feet warm it kind of defeats the purpose.