Ipad vs GPS unit

[goughy]

You're incorrect. cell versions have an integrated gps. cell signals are only used to assist the gps for faster location acquisitions but aren't necessary to obtain a location lock.

Yes, that is what I was saying (or intended to). I was pointing out that the updating of maps and turn-by-turn directions would not work without cell coverage. All map information must be uploaded to the iPad beforehand.

The cell network has no effect on the ability to obtain a position or on its accuracy. The approximate coordinates provided by the cell network will assist in providing a faster lock in situations where the previous GPS-calculated position is a long way from the current location.