i have a two year old Kick *** Quilt Potomac underquilt. It is homemade out of 6oz of climasheild and two extra layers of insultex. Last year I would take it down to the twenties and stay very warm. The Potomac was extra long and fit excellently on my HH ultralight Explorer. I always wondered why there was never a down version of the Potomac underquilt on the market. It could be contructed and modeled to fit like a giant down Yeti underquilt no doubt. I think that if Brandon made something like that that alot of people would buy it.