Ordered the upgrade from Navigation.com, it came with a map data dvd and a radio firmware update (v2.404). It took about an hour to install both. I can't notice any difference in the firmware upgrade (from v2.402), must be a minor tweak.
As far as the map data is concerned, there seems to be no difference for the area near my residence. A subdivision that is over two years old is not on the map, and the POIs look the same. A couple of businesses that have been closed for over 10 years are still shown.
Overall, I am disappointed in the upgrade, seems a waste of $149.