I purchased the Garmin world map. As expected, the detail on this map is not very impressive. However, since I have been adding the information that interests me the most (The Great Wall), and since it’s intended more for off-road use than for driving, it should be adequate.
I have been doing some real-world testing of my GPS receiver, a Garmin GPSMap 60CSx. The tests and results are detailed in
this thread. In general, I was very impressed with the performance of both the receiver and of Energizer Lithium disposable AA batteries.