Strengths: Convenient, easy to use. Much more stable than expected.
Summary: Overall works much better than one might expect. It stays quite secure and can easily be switched from your own car to a friends, rental, etc. It does stay where placed; the only time it has moved is after going over some rough bits of highway at 70mph. It would just bounce off the dash a bit (which was a bit nerve racking at the moment). Only other gripe is it is quite pricey after you buy the connection bit to go along with it.