http://borahgear.com/vest.html
Borah gear is now offering a 3.6 oz (M) down vest for $100. It has 1.7 oz of down, so close to half of its weight.
One of the only pieces that I've ever really regretted selling was an old montbell down snap vest which weighed 3.75 oz and compressed down to nothing. I've been on the look out for something similar for a while for light summer trips, longer mountain runs and supplementary warmth in other seasons. Seems like sort of a niche SUL product at first glance, but to have warmth that compact and light in your kit is surprisingly useful. Also the introductory price of $100 is a steal, IMO. Just put my order in. Looking forward to adding it to my kit!

