Excerpt: The Marmot Hydrogen is an ultralight down sleeping bag available in both regular and long. The bag is only available in 30 degree Fahrenheit rating, so it is a nice bag for cool weather hikes or excursions where weight restrictions are important. The bag is filled with 850+ goose down, which has the best weight to warmth ratio of any down insulation on the market. The Pertex microlight shell is light, breathable and water resistant.
Excerpt: These are questions you need to ask yourself before you buy a sleeping bag. The answer will vary depending on what you want to use your sleeping bag for. You want a 'do everything' sleeping bag? So do I! However, a bag that keeps you alive in a Himalayan storm is also unlikely to be comfortable when you're bivvying at Cloggy on a warm September evening. They are all tailored to a specific temperature range. The heavier the sleeping bag, the warmer it will be.