I'll agree that the Precip is not breathable. Have one for a few months now, use it occasionally when walking to work, if it rains or is really blowing and cold, it's always in my 10 litre backpack anyway. Waterproof yes, good in a downpour, but don't expect it to dry, inside or out in a hurry
If I put it on and walk, for example, a mile, it'll be wet on the inside. End of. Hence mesh pockets, to ventilate. Arm pits, to ventilate.
Whereas, my Buffalo Windshirt (Pertex, in my hiking backpack), now, that's breathable 100%, no question.