well, these observations themselves are influenced by expectation. It's also an unfair test because I don't know how many different tanneries make the other soles, since they don't mark their soles with ugly branding. I've heard that Baker outsoles are just as good if not better. I wouldn't be surprised if a couple of the French chestnut tanneries perform just as well, and there are probably some good italian ones too. I hate to perpetuate the groupthink because in general I think these things should be left up to the craftsmen who have experience in their material choices and probably don't need a customer telling them they should use X leather soles because someone on the internet told them that noone else knows how to properly tan sole bends.