I have been an ultra light fanatic for years and always look to shave an ounce or two. As far as sleeping bags go, in recent years I have added Italian, and French made bags, two major U.S. manufacturer's down bags, and a couple of those specialty manufacturer's sleeping system thingies! I must say the Hydrogen is lighter, more comfortable, packs/stuffs better and is far, far more full featured then any of those other bags. It is perfect for any weather we encounter spring and fall, and in summer it is light enough to take along as insurance as it packs easier then most 45 degree bags and you can unzip it for those July/August hot nights as its not one of those horrible cocoons! I have found it so versatile it has already replaced all of my three various multi-season bags I used to use. After a five night trip and two weekend trips, I can't yet vouch for the long term toughness, as the materials are not exactly heavy duty, but I have found it very well made, and able to handle whatever we have faced so far with no runs, stuck zippers or punctures! A bit pricey for a thirty degree bag, but I think well worth it. MP.