I bought this as a trail running jacket for the winter time in NC. I wear it over a long sleeve athletic shirt and that is it and I only really wear it under 40 degrees F. It works great, I have yet to overheat in it and it seems to keep me a magical perfect temperature. If I get cold, I flip the hood up, if I get warm I unzip a quarter way. I like the thumb loops too and it's super light weight. I know there are other jackets that are lighter but I can't think of any reason you'd need one lighter than this. The mountains have a good wind wip and this cuts the wind perfectly fine for me. Only complaint is the sizing might be a tough off. I am 6'2" and 165lbs and I got the large. It fits in the arms great and is a little roomy for layers underneath (not a problem) but my complaint is with the zipper... it bulges outward near the waist line giving the impression that you are a little too happy (if you know what I mean) to be running. Maybe a medium would remedy this but I think I'd lose the arm length I need at that point.
Gar the Goat
North Carolina mountains