Trying to decide between a Montan 600 or 650. Seems the only difference is the 650 has the built in camera. Besides that the side by side specs look identical. Just wondering if the camera is worth the extra expense and if you actually use it? I don't really want topo because from what I have been told the City Navigator has pretty much any trail or fire road on it I will ever use. Just wondering if I really need the camera?