In this video, I compare my gore tex pro shell (Outdoor research mentor) to my eVent shell (Rab Latok) in breathability. Both are 3 layer shells, each of them were just washed and ironed w a steam iron. This is not a scientific study but rather a qualitative measure although I did try to control for as many variables as possible. Both are very breathable but in this test it is evident that the eVent breathes sooner w a higher flow rate through the material. I have also tested the conduit material from mountain hardwear but didn't post it because it paled in comparison to both of these materials. It did breathe but it took a long time and was at a very slow rate. Hope this was helpful.