Well, it's early for one. Baseball season just wrapped up, the game doesn't come out until March/April, and other sports will be launching with the system, making them more "up front" at the moment.
Plus, while it's definitely a big feature, it's also difficult to truly measure its impact until we can see it in effect (which really won't be until MLB 15). Currently, we don't even know how it's
intended to work, let alone that it
does work.