Directly comparing the Zeta with its Gore Paclite Plus fabric to air-permeable models isn't as cut and dry as it sounds. Air-permeable models have a lower but more static level of breathability. In contrast, this model, as well as other models that feature any variety of Gore-Tex, can have higher and lower levels of breathability depending on the level of activity of the user and environmental factors (like the temperature outside). This level fluctuates more depending on how much internal heat build-up there is relative to the air temperature and to a lesser extent relative humidity (which for most people means generally higher when you are wearing a rain jacket). When we were working hard (such as hiking), both Gore Paclite Plus and Gore Active breathe better than any model featuring an air-permeable fabric, such as the Outdoor Research Microgravity and the Rab Kinetic Plus (the two best). However, these models performed better if it was exceptionally hot and humid out, or once we had cooled off (say, while setting up camp).