I like that kind of thinking, simplicity over complexity. I'm not sure why it was changed, but they might have felt something more dynamic sounded fun (chits seem more dynamic to me, anyway, since you can actually like..."use" them). They did mention up there that they want to see it in action for any kinks to be worked out. So if there really is a fatal flaw, it'll probably show it's ugly face pretty quickly. And if not, then it may be "glossed over by the characters anyway", if complex < simplistic. XD C'est la vie, right?