For the price, its hard to find a lighter bag. The rating is about right, but your sleeping comfort is highly Dependant on other factors such as your sleeping pad. In 50 degree weather, I use this bag like a blanket with a R3.6 inflatable pad.Packs a bit larger than a 1 liter nalgene bottle. Though thin, the fabric feels surprisingly durable. I would agree with the assessment of Alex on Dec 11. Good 3 season bag. The only reason I would not give it a 5 star rating is because of the way the spiral bags are made, there is potential that the down can be packed into one side. The down filled pockets aren't sealed and run diagonally across the bag.In retrospect, I think I should have gotten a 20 degree bag and a 45 degree bag.