The other sacrifice is the size or thickness of the bag. A mummy sleeping bag essentially will certainly be much smaller sized for bring around which is why it is a preference for many backpackers/hikers. The rectangular resting bag isn't as small yet because it's not common to be lugging it, apart from somewhere in a vehicle while getting to your intended location, the bulkiness of the bag is not as large a problem.
Goose Down Resting Bag: There's nothing with a greater weight to warmth proportion when compared with down. A Goose Down resting bag is extremely light-weight. Down is only for people most diligent in maintaining their sleeping bag completely dry. Hood: as detailed previously with the Mummy Sleeping Bag, a hood having a drawstring could assist keep temperature.
Rectangle-shaped sleeping bags go as much back as the late 1800's when a mail order catalog pioneer Pryce Pryce-Jones came up with the suggestion to attach 2 rectangular carpets together with ties. He is taken into consideration to be the innovator of today's contemporary rectangular sleeping bag design. After the war he had several of these bags still left as well as made a decision to market them to the public.