I'm not sure how I missed this, so sorry for the extremely delayed response. The Kor Preshell is pretty good I would say as an active wind blocking layer. It's very breathable and light and weighs almost nothing, but I'm not sure I would pay full price for it. It's horrible in any kind of wet weather, but maybe that's just the DWR coming off. I actually got an OR Ferrosi that I wear more often at the 9 oz penalty as I find it more versatile. I also have a Marmot windbreaker vest but that has a thin fleece coating in it so not as light or breathable as the other two. Still haven't found the perfect layer combo while being as light as possible.