Not worth it. You can get a much better Nav system from other vendors (such as Garmin, for one) much cheaper. And it does not stay with the car.

That said, I am glad I got my Nav system with the Camry. Although it does not have the features that my portable has, it is convenient since it is built in the car and it does show the hybrid data. But, with my purchase negotiations, it was pretty much thrown in on the deal.