I used Nokia Drive today and was somewhat disappointed. Although it was very accurate, I needed to depend totally on the voice instructions. There was no overview of the route to give me a general feel as to what was going to happen next.
On the way home, I used maps and actually the navigation. I saw the directions all listed and felt a little more secure. I really only needed the first few directions to get me to a freeway. By looking at the overview and committing this to memory, I felt more confident and not so lost.
These are just my observations as each person will have his own comfort level.