I’ll confess I would have a nerdy admiration for ExpeDry down even if it didn’t work, just for its use of basic chemistry, which even I dimly remember from high school but for some reason never made it into a product until recently. What’s even better is that it does work. I don’t have a lab, and I’m not particularly interested in what happens in one anyway, but I am a backpacker, living in a cold climate, with a deep dislike for being cold. In the real world, where I live, if your jacket loses loft and you get cold, bad things happen. In my testing, the Vantage jacket loses almost no loft throughout the day, even when I am active and sweating in it. Better Than DWR? Photograph: Scott Gilbertson Outdoor Vitals is not the first to use ExpeDry. Marmot, Katabatic Gear, and many others also have various sleeping bags and jackets with ExpeDry down, but the Vantage is the first time I have noticed a real difference. The Vantage has less fill than …