I have the nav system in my '04 and I love it. It is not perfect, but no system is. The maps are very detailed, the CPU is fast, and the features are too numerous to mention here, but I will highlight a few.
You can input a destination address by 1. entering it with the virtual keyboard, 2. selecting it from a huge list of preset catogorized destinations, or 3. Searching with a cursor and selecting the current cursor position.
You can select from a route preference list for things like via highway, avoid highway, avoid tolls, shortest route, fastest route.
You can select to display the route list which lists the route in segments, sort of waypoint style.
You can select north facing, or vehicle orientation facing map display.
Also has a split screen mode to show 2 functions at the same time (i.e. map and directions, radio and directions, OBC and directions).
It gives detailed directions in the Directions mode including current location street and city, next waypoint street, next turn direction, general destination direction, current ownship general direction, arrival time, and intersection detail.
Pleasant (not sexy) female voice instruction, which can be defeated.
Many, many other features.
Any specific questions?