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.
Rectangular sleeping bags are the initial and also most typical form you'll see on the market. I directly don't think there is much of a visible difference in between the fillings nonetheless synthetic fibers will certainly not soak up water and will certainly keep you warmer also if the bag is a little bit wet. A damp down resting bag is very hard to dry out as well as is taken into consideration even worse than having no sleeping bag at all.
The last greatest factor to consider in selecting a bag is the insulation that is used in that bag. While both will do the work to maintain you warm, they both have their pros as well as cons. Some kind of extra padding under the bag is very advised.