I've been thinking about buying a silk mummy bag liner to take my quilt down a few more degrees, and help keep the gear a bit cleaner too. And have sorta zeroed in on the cocoon expedition ( I particularly like the hood idea). Have been reading the reviews and they'd giving me pause to re examine this possible purchase. From the reviews I'm starting to get the impression that they don't add any appreciatble warmth to a sleep system. Last camping season I was a cold one night when the temps got down to around 34 ( diy down quilt that I targeted for 30) I was hoping that a silk liner would add 5-8 degrees . anyone else using such an animal? If it doesn't improve cold range, I'll have to change tack