Mine is a different story. In fact, mine was the opposite of what most people had encountered here. I started out using B+W MC filters 15 years ago (they were not as expensive then compared to now, BUT, their prices were still very high for the average photographer). Anyway in less than 2 years after my purchase, the coating on two of my polarizing filters were beginning to flake badly. It started out as tiny crack lines and eventually the coating came off. That was one hell of a bad experience I had from such item, supposingly to be high-end.
After much hesitation, I changed all my filters to Hoya. Mind you, they don't have the Pro 1D or Super HMC series back then. It was just plain HMC. And boy, my Hoya polarizing filters lasted me 6 years before I finally got sick of cleaning the filters and decided to replace them with new ones. Yes, I must agree that Hoya filters are harder to clean compared to B+W. But if you don't mind changing new filters every two years, I don't see any reason why you should settle on something that cost 3 to 4 times the price BUT it does not give 3 to 4 times improvement.