Since the overall ranking of a quarterback is in many ways dependent on the makeup of his team (thus affecting his numbers), I think you need to look at the bigger picture, including areas that are in the quarterback's control (such as keeping in shape, studying, and working out). When I look at Ben, I see someone who doesn't really focus in the film room, doesn't hit the weight room, and someone who isn't in shape or focus year around. He always seems to throw a few bricks his first game, every season, as well as getting to camp out of shape.
That, in my definition, isn't an elite quarterback. That's someone who has enough talent and moxie to get by.
I believe that, judging by historical trends (quarterbacks who get by on talent), once his talent starts to erode, it will erode fast.