Down's amazing until it gets wet. Mountain Hardwear's remedied this drawback infusing its down with Q. Shield, a permanently water repellent treatment that'll keep your insulation lofty and warm even if you get a little bit soggy. That means the Nitrous' 800 fill down will stay cozy no matter what, while its insulated low profile hood and dual hem drawcords seal in your heat and prevent drafts from creeping in. The whole package packs down into its own pocket, too, so it's easy to carry in your pack on the rare occasions you're not wearing it.