I may not be as experienced as you even though I have been hiking off and on in Washington and Alaska some. I have always had down sleeping bags since I was and Explorer Scout and they have never gotten so wet that they failed to keep me warm. Now I have a bag (two actually) with a highly H20 resistant cover and feel really comfortable with it. So I will not switch to Hydrophobic Down. I have seen water bead up on my new bags and i simply brushed it off. Also, perhaps an aside: I have slept in heavy rain in a Gortex Bivy sack (Moonstone) with out getting even damp inside. Again, water rolled off, never wetting-out the bivy sack.