In reply to Flat4matt: with these light weight down bags its all in the fill power (and having goose down). high quality high fill power (750+ ish) goose down is a totally different beast, it looks nothing like feathers whilst lower fill power does look more like feathers and will have more feathers mixed in and is often duck. high fill power lofts much better and retains that loft for much longer with use. I remain skeptical that any bag with a fill power of 500 and weighing 750 grams will be keeping you warm at 1 degrees after couple of years of use. in my experience these bag ratings are variable between manufacturers, but the extreme ratings are worthless stick to what they call comfort. imo.spend the money on a better quality down, have you looked at the alpkit bags?