The main reason I want a jacket is for it to be a wind barrier to keep from getting chilled especially on long descents. Because of that, for me, I really don't see being air permeable as a huge plus in a shell. I don't mind being wet until I am wet and cold. I think that I'll just continue to use a non permeable shell and use zippers to regulate the warmth. It works pretty well for me so I am really not looking for a solution, since I really don't find what I am doing to be a problem.