The significant difference between both styles is the cut and also form of the bags. The mummy bag is extra restricting. You can think about it like your own individual cocoon where you can go to bed in the evening as a caterpillar as well as wake up the next early morning as a butterfly. You're completed tight with not a lot of area to relocate. The rectangle-shaped bed on the other hand gets its name from its rectangle-shaped form as well as lets you relocate your legs.
An additional kind of sleeping bag is the mommy bag. Unless you are intending a trip to an extremely cold climate and resting outdoors after that you will possibly be happier with rectangular sleeping bags over a mommy style bag. These bags have a certain use as well as they are extremely particular, extremely cool weather condition, mommy sleeping bag.
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.