I got this jacket s a running layer and for casual wear because the design is that cool and have been very impressed with it. When most running jackets say "windproof" and "breathable" i never believe it becuase it's usually not the latter and ends up feeling like you're running in a sweatbox. Not the case with this jacket as the material is indeed breathable and has some vent holes in the armpits to allow heat to escape. The material is super soft and i loved the small touches like the reflector strip on the right shoulder, the thumb holes, and the larger zippers that are easily accessible when you have gloves on. i've run in this in the 50's and 30 degree ranges with different layers and it still does the trick. My only criticism is that you may want to size down. I initially ordered the medium (i'm 5'11" and 162lbs) and returned it for the small. Hope more running stuff comes out in the future from Roark, especially some shorts that are shorter than 5" ;)