I really like this top. Wear it out running when it's just too cold for a light sleeveless top.
I bought the large, which should be a tighter fit, but it's not. A bit too lose around the waist and arms. Hence one star knocked off. Neck and zip is handy after your run, keeps your heat in your body. It's nice and high up to the chin. I've worn it on it's own, in windy weather, held up well. Sweat wicks away, and didn't feel cold.
Usually it's worn over a running top, and serves it's purpose well on those cold days.
Drys quick after a wash too. For the money, you can't go wrong.
EDIT march 2013 - Bumped from 4 to 5 stars. I'm still using this, and I have to say, it just be best top ever. Still like new. Still dries in no time, wicks rain and sweat away. It has paid for iself, not like the Adli running gear I got a year ago. Well done Helly Hansen, I will be buying your stuff from now on.