TomTom GO 300 GPS nav system

I have seen awesome reviews about the TomTom GO 300 GPS receiver, every site I go people say wonderful things about it. In a BMW club web site they even say it is better that the factory option. It may be a great alternative for us without the Factory nav system. Has anyone installed it on the Armada or used it? My only concern is leaving it in the truck. I do not think it will last a long time. I am seriously considering getting one and hiding it inside the glove conpartment at night when I get home.