I've often questioned the compressed sleeping bag's ability. If you leave a bag compressed too long, you have a permanent loss of loft, and most military survival items are packed and left alone until they are taken out of inventory unless they have a due date on them (meds, rations, batteries, etc). Something that was vacuum packed and stuck on a shelf or in a pack in the belly of cargo bird or B-52 in the 70s just doesn't inspire my trust.
If you are going out in winter, get a proper sleeping bag, and pack it when you are going out. The rest of the time, leave it unpacked, uncompressed and some place where it can breath. It will cost more, might be a little bigger, but it WILL work as advertised.
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-IronRaven
When a man dare not speak without malice for fear of giving insult, that is when truth starts to die. Truth is the truest freedom.