When a manufacturer of a unit claims that North America or 50 US states are programmed into the unit- does that mean all of North America or all of 50 states or just preselected ones? I am not so much interested in POI's as much as I am in getting from City A to City B or finding streets within a city such as addresses. Currently I am researching various models of TomTom, Magellan and Garmin. Any thoughts. Battery life is important too.