User Review: U.S. Armed Forces Modular Sleep System MSS
Forget the silly $500 sleeping bags. Get a 3-part MSS, which is very similar to Wiggy's FTRSS. Comes with 1 lighterweight "patrol" bag rated 32-50 degrees F, the intermediate cold weather bag for 0-32 F, and a Gore-tex bivy cover. In moderate weather you've got bags for two people. In cold weather, use all three, with some layers of ECWCS stuff--longjohns, grid fleece, and an outer fleece layer, and the set-up is rated down to -40, and claimed to give 4 hours of sleep at -50. (I'd add a fleece cap, I think!)
No wishful thinking, optimistic temperature ratings here--this system is tested and rated by the Army's testing labs in Natick, Mass. It's a roomy mummy with a big footbox, tough zippers, and is machine washable. Plus, like Wiggy's, they're made in the USA. No horrid Communist Chinese factory output with this product. And, it's low key--the latest version has two shades of green for the bags and ACU digital camo for the bivy. The version up until about 2005 has one black bag and woodland camo. No painfully bright colors here.
Look out for, and avoid, the cheap Chinese knock-offs. You'll find both the real and wannabe versions on eBay. The real deal is made by Tennier Industries. All in all, a compact, superbly-designed and built bag. Best of all, it's warm, warm, warm!