Posted by: willowleaf on Mar-12-13 2:50 PM (EST)
I've been pretty happy with a Kelty synthetic semi-mummy I got about 8 years ago (previously I had mostly used down bags but find this one just as comfortable). I see Campmor has a rectangular Kelty Callisto 20 degree mummy on sale for about $80 at the moment. Also a North Face Dolomite 15 degree bag for $110 and a Slumberjack Timberjack 20 for $70. I like the Kelty bags for quality of materials, warmth and compressibility. I've found I can easily use a smaller stuff sack than the one they supply to reduce the packed size.
I have mixed feelings about waterproof fabric bags. From all accounts I have read they tend to not breathe all that well and you end up clammy inside. My preference is to use a Goretex bivy sack over the bag if I know I may be exposed to rain (like camping under a tarp or lean-to). And they are goddawful expensive -- a separate bivy is cheaper. In fact I made my own double bag bivy using a 2 yard length of Goretex from Seattle Fabrics stitched on three sides to an equal sized piece of coated nylon packcloth (for the underside). Cost about $100 all told, far cheaper than the premium for waterproof bags. And easier to wash and to pack separately.