[Fins]

That's all nice and well, as long as you are in cell tower range. I drove mine cross-country through places where you get 0 cell coverage. Having a navigation system that actually works is pretty nice.

[wvenable]

Navigation on a phone doesn't require cell coverage -- it works the same as your car, just download the map you need.

[Fins]

That at the very least presumes that you remember to do that in advance. And that this functionality is actually available to do. Last time I tried, e.g. Google Maps would not download offline maps in some countries.