Just to curtail any confusion here..<br><br>I believe Bagheera is speaking of the NEW modular sleep system. The two bags have synthetic shells with synthetic fill. I don't think he's talking about that nasty old green cotton sponge.<br><br>Bagheera, it if IS the new MSS that you're talking about, I can tell you that I was impressed with it. It was definitely one of the best gear items I had when I was in the Army. My strongest impression of it was when I was at Fort Polk, Louisiana in January. Using the black bag, green bag, and goretex shell, I slept through an ice storm without realizing how bad the weather was. This was completely in the open with no extras except for a sleeping pad and polypro longjohns.<br><br>In the morning I had to break the ice of the goretex shell before I could get it into my rucksack.<br><br>If I happened to see one of these systems at a surplus store or a gunshow, I'd buy one (unless the price was completely outrageous).