What part of... ...don't you understand? If it's raining that hard you're not just walking on wet pavement, you're in puddles continuously. In such situations not even a hand welted shoe will be waterproof. Moisture seeks dryness, that's the basis of leather's ability to breathe. It will get in all along the top surface of the welt, along the interface between the welt and the upper, through the upper itself, it will wick in everywhere it can. But it can't pass through rubber. Period. If I coat an outsole with neoprene cement on both sides but leave the edges uncoated and then drop it in a bucket of water the whole outsole will get wet eventually. From the edge inward. Bubbles of air will come streaming out so fast and furiously that you can actually hear a thin scream coming from the leather. But if I coat those same edges as well as all other surfaces, it will never get wet. And again, no one said that a good rubber outsole wouldn't keep your feet dry ...a pair of Tingleys will do the same thing. Nor is anyone saying that rubber won't last longer than leather esp in wet weather and on concrete. But if you follow the logic to its obvious and inescapable conclusion, you've just made a brilliant case for corrected grain or vinyl shoes with a heat molded rubber outsole and a rubber insole. Take the label off one of your St. Crispins and glue it to your Crocs and your every wish will have come true. Other than that I can't speak to your shoes or the makers' techniques.