[alister]

I would add:

- Privacy. A dedicated device with a one-way incoming signal (GPS) and no out-going signal cannot track you. This is not true of any smartphone app no matter what they claim or what their settings are.

I'll grant that the privacy benefit is pointless for the overwhelming majority people since they will leave their universal tracking device[1] turned on anyway.

As an aside: I was impressed that my really ancient Garmin, which displayed only latitude, longitude, altitude, and recorded waypoints, had a special button combination to instantly and securely erase everything it remembered.

[1] cellphone :)