Goretex does well because it is a porous teflon. Teflon has a very high dielectric constant. This causes the water to bead on it, similar to the flour containing waxes (teflon also contains a flour bond). This will mean that Goretex could let through quite some air without letting in water. Another porous teflon is E-vent.
With Polyurethane membranes, the working is more like a wick. They get wet on the inside and transport the moisture to the outside to be evaporated. This membrane can get saturated more easily.
Porous teflon is used more often in the expensive equipment. The Polyurethane option is seen more often in the cheaper stuff. Goretex jackets are expensive due to 2 components. 1: The manufacturer pays extra for the goretex brand. 2: The jacket needs to be approved by goretex, since the "guaranteed to keep you dry" guarantee is given by goretex, not the manufacturer. Goretex might thus require extra measures to approve a garment. The first component is a pity. The second could make a difference, though good brands know how to make a jacket waterproof.