I used it 4 days in sub freezing and absolutely loved it.
I'm 6ft tall and wide in the soulders, and had plenty of room to move.
The only thing is that it takes time to warm it up (because of its size),
but once you warm and keep it closed around your neck, you will sleep like a bear.
I have the large size, and I'm buying one for my father-inlaw.
This review was written in the old system and had content requirements that are different than reviews written today.