I like the feel of Hobbs PolyDown. The quilt ends up light in weight and very soft.
What brand of cotton batting are you using? I find Warm and Natural to have a stiff drape compared to others (it does soften up with repeated washings), and it is heavier in weight than I like. My favorite cotton batting is Mountain Mist Blue Ribbon 100% cotton, but it is thinner than many quilters like. Weight is similar to Hobbs PolyDown, but it does not have as much loft (a more flat, traditional look). Hobbs 80/20 is a nice batt that I would place somewhere in-between WnN and MMBR -- lighter than WnN, heavier than MMBR, with a loft closer to PolyDown but not quite as much loft as PolyDown.