I grew up to take MB navi systems as a toys only, not really trip planner.
On 2001 model, when coming down from the woods, the thing would always put me in the middle of the lake near by,.
Our 2004 model is pretty impressive with voice command and on cluster directions, but once, starting on the street that was parallel to the freeway, the navi wanted me to drive the opposite direction, than the destination and to top it, on smaller streets, when shorter route had 45 mph highway to the freeway.
I've been using Delorme, computer based GPS for almost 20 years and it is hard to beat big screen, with dual windows showing different map scales, where I can easy say if I am routed around the city.
Sure computer on passenger lap is not always the most convenient, but on long trip I plan it on both GPS and compare the distance. When in doubt, I zoom on computer to see what is going on.
To top it, yahoo maps are pretty current, when any GPS is about 8 years outdated in the moment it comes on the market.
