There are primarily two types of sleeping bags. One is the mommy bag and the various other is the "traditional" rectangle-shaped resting bag. Currently mind you, ain't nothing incorrect with old school in any way. It might be your preference once you uncover just what it's like verses the mommy bag.
Remember that with time, from typical use, a treking sleeping bag will certainly lose its warming performance. This results from the fill obtaining a bit much more compressed. This will cause the "air pockets" to go away.
The shape of the real resting bag is to personal preference. The general selections are the normal rectangular form, the conical form, or the mommy bag. Some individuals might not such as the feel of sleeping in a regular rectangular shaped bag, favoring the closeness of a tapered one, whereas others may really feel too claustrophobic.