Tom...I have some original Gore-Tex stuff from about 10 years ago, an LL Bean Mountain 3 ply jacket. I also have a couple of Marmot's with their take of a Gore-Tex membrane. Recently, I purchased a Gore-Tex Pac Lite jacket, and to be honest with you, the "breathability" of all of these items is questionable at best. The most all-around comfortable, is the oldest....the 3-ply LL Bean Mountain jacket. Ed