I have probably done a thousand pizzas (is that possible?) since I dropped the San Felice, and, honestly can't remember a speed difference between SF and Caputo. But as long as you bring it up, what do you mean by "fermentation was faster"? How do you measure this speed? If you are referring to volume growth, I would argue that is only part of fermentation. The development of flavor is a big part of fermentation. The only way I know to truly measure this is when the crust is in your mouth.