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.
Semi-Rectangular: I call this the cross. This backpacking bag is rectangle-shaped ahead and afterwards slenders along towards the feet. With this type, you obtain added space, but not as much weight as a true rectangular resting bag. For those who are claustrophobic, like me; we can reach sleep a little better inside a bag with added room in it and still have some benefit from the form.
Rectangle-shaped shaped bags are one of the most popular and also most acquainted. These supply you with even more space for movement within, lowering that claustrophobic feel to some degree. Since they are of a square form they could also be whized to a 2nd to generate a double sized resting bag, huge enough for two individuals to sleep in. Or, if you completely do not like the feeling of being zipped up, you can leave the bag unzipped completely and also utilize it as a blanket rather. These bags are typically rather huge, and also might not be perfect for treking trips as they can be instead bulky and unpleasant to carry.