It is exactly what you experience that convinced me to get an 800. The problem I had with the 500 is that when you get 'off course', it doesn't help you get back. In unfamiliar territory, that's just as good as being lost. In addition, it always told me to turn, right when I should or when it was unsafe to do so. No advanced warning. Maybe I just don't know how to use the silly thing. The map capability of the 800 with turn-by-turn directions is well worth the additional cost.