We are all familiar with the down verses synthetic sleeping bag debate. Each fill has its advantage and its disadvantage. So which to choose? Down sleeping bags are often go-to choices for backpackers because the fill offers more insolation for the weight, and is far more compressible than synthetic fill. Unfortunately, those of us who live in damp climates can often find themselves shortchanged by down sleeping bags. Once down gets wet, it loses much of its insulation power and—well, you may find yourself wishing you had bought a different bag.