Quilts are fine when the temperature is somewhat warm. Just as well go with a full bag in below freezing temps, as by the time a person cuts out the drafts with an extra long and extra wide quilt, the thing weighs nearly as much as a regular bag. I've gone back to sleeping bags in cold conditions. That cutoff point is person dependent - I'd rather carry a few extra ounces and stay warm and cut out drafts, but others sleep more comfortably with the extra room of the quilt.
