I started out with a premium down bag. I still have it, but years of repeat compression and soiling have taken a toll. I tried the moisture barrier system as promoted by Stephenson. Warm? Yes, and when you crawl out that sweat chills you while towelling off and dressing.Modern materials are very good, but they do wear out and collect water ( ice). The Wiggy is a heavier system. It is machine washable, regains loft vey well and has a superb garantee and customer support. The only complaint I've heard is again the weight ( ultralight backpackers). Would you rather have a balsa wood and aluminum knife?