The maps situation is clear, and I agree that the specs should technically be the same. My point, however, was about production quality of the individual units. Every manufacture produces non uniform quality items, and the way these might differ here would be in longevity. So what I'd guess is Merc bins the best units for themselves, and the lower quality stock goes to the customers. The complexity of the aggregate makes it impossible to detect this externally , unless someone from the factory actually comes forward.