I admit I bought this thinking it was just a fall/spring running layer. It is so much more than that. It's now the cornerstone of my upper-body layering in all winter sports. Skiing, climbing, hiking and ice biking. It takes a bit of getting used to to realize how many layers you can leave at home with this on, but once you do, winter (even in the northeast) becomes a lot lighter and more comfortable.

The seams could be a bit smoother, and it feels plasticky the first dozen or so times you wear it, but it's such a good piece otherwise that despite these downsides it still gets a 5.

Wore for 5 days straight while spring mountaineering in the Sangre De Cristo's. Perfect by its self while carrying heavy pack and postholing while its snowing and windy. It was also great as a layer when it got around zero. Great for reducing the layers i had to carry into the high country.

Whoa! This absolutely one of the best pieces of gear I've ever owned (and that's saying something). I can wear this mountain hardware top with a thin arc'teryx soft shell over it and I'm good to go backcountry skiing when it's 25 degrees. The featherweight zip is also great for trail running or any outdoor activity. This shirt breathes really well yet it's wind proof, insulates you amazingly from the cold, doesn't overheat. I could go on and on. Well worth the money. I may get another one.