When I grew up in scouts in the late 80's/early 90's, my dad had some 15 degree army down bags that we used that he had picked up surplus in the late 60s. Not that lofty, cotton shells, often cold. They had water resistant cotton covers we could add to them to raise their rating and (frankly) to save them from destruction. We loved them.

For all of you who know what I'm talking about, how do you think one of these: Western Mountaineering Mightylite compares?