I got this jacket on sale, and found that for about $30 it is a really good jacket. I bought a medium, which is my usual size, and there are some fit issues that probably would have pushed me to return it if I paid full price. I am 36 bust, 28 waist and 38 hip, so right in the middle of their recommended sizing for medium. The jacket fits, but it is surprisingly tight in the upper arm sleeve. Thankfully that material has a little stretch so it's not a big deal, but I have to make sure to wear a very thin base layer underneath the jacket or else it becomes too tight and restricts comfortable movement while running.

I've mainly used this as a layer for running and it has been great for that. I consider this an insulated base layer, it has replaced my half-zip and vest combo (over a t-shirt) that I turn to for runs in 20-40 degree weather (in Colorado for reference). Depending on how cold it is I have a down vest or a fleece vest, but this jacket has done really well at replacing both. I will say that I run hot, and I am usually the first person in the group to take off my layers during a run, so if that's not you, this may not be warm enough. (I am not bold, and never start cold)

The insulation on the chest and back is really cozy. While I've only been using it for cold weather running, I imagine this transitioning to a hiking jacket when spring arrives and the temperature finally gets above 45 degrees.

Sleeve length is awesome - I'm 5'10" and sleeves are always too short, but not with this jacket! It fits well throughout, and is the perfect amount of warm.

More like a shirt, the word jacket is misleading, it is not cozy, barely insulated. Did not do the job while running in 45 degrees with a thin base. A thicker layer underneath looks dumb since it's a slim fit... IT dif fit well as a sweater though, true to size, pretty color, got the burgandy.. xs. I am 113lbs. 5 feet tall.. it was overpriced at 38, which I paid for it..$20 would be a reasonable price..since I wore it running, I guess I'll keep it now but as a sweater for porch sitting.

Just a note on the fit so it doesn't get buried in the rest of the review - this is a relatively slim fit; the sleeves especially are more like a stretchy athletic top than a jacket. I wear mine over a baselayer, but I don't think it would fit over another sweater the way some hybrid style jackets do. Anyways, with that out of the way – I'm such a fan of this! I just took it on a mountain bike ride during our first snow day, which is kind of the worst conditions for most jackets - cold, but not cold enough to justify a real puffy, and there was a lot of opportunity to overheat on the uphills. This really did an impressive job of keeping me warm when I needed it, without being too much. Seems like it'll be really versatile! Definitely worth a try if you need a light insulating layer that ventilates well.