UPDATE after using jacket for about 1.5 years: I've had many puffy jackets, but this is my favorite of all time. It's very warm for it's weight, and it's holding up well over time as a belay jacket and as my puffy for backpacking. Everything I've written below is still true. UPDATE after using jacket for 4 months: Overall excellent. The jacket is exceeding my expectations. I'm using this as a belay jacket, and as part of my standard layering system for multi-day backpacking trips. It's warmer than expected, allowing me to leave heavier gear at home. I was nice and warm at temps around 25F (-4C) sitting around camp, with a wool fleece and t-shirt underneath. I suspect it could handle colder weather with good layering. I've only seen it shed a couple of feathers which is decent. Breathability is about middle of the road, not the best, not the worst. It breaks the wind nicely. Thin fabric seems to be holding up good with nearly daily use - no tears. Stitching remains solid. I'm also surprised at how good the cut looks. I've started wearing this Jacket casually during the winter. My wife wants one. My only feedback for improvement on the design is that the armpits area should include a bit more room for increased mobility for the shoulders / arms. ORIGINAL review: Excellent Jacket! I've been looking for an ultralight down jacket for years for backpacking or climbing in high alpine environments. I had never heard of "Dark Peak" before, but found a review of the Nessh jacket online. I had been planning on buying the Feathered Friends EOS jacket, but I bought the Nessh instead due to more insulation, similar weight, better price, and the "buy one - give one" policy. I haven't used it for climbing or colder weather yet, but my initial impressions are very positive. On a recent backpacking trip, the Nessh was very warm for the weight. I even got caught in some light rain without my rain jacket, and the Nessh repelled the light sprinkle without problems. The exterior fabric is thin, but it seems durable enough. The sleeve cuffs are awesome. I'm 5'10, small but athletic build. Based on posted measurements, I tried the small size, but it was too tight across the shoulders. The medium fits perfect, which is my usual size from brands like Rab or Arcteryx. Dark Peak was very good to work with, and they handled the return / exchange quickly. I was amazed at how quickly I recieved the jacket because I live in the USA. Highly recommended. I will be sending my friends to Dark Peak. My wife loves the jacket and wants one of her own. I hope more people can discover this great company!