I drive but rarely, and finally had a chance last month to use my phone's voice-prompted turn-by-turn navigation mode. It was great! Like any human navigator I've ever worked with, except never hesitant or uncertain and always on the ball with the next turn well in advance of reaching it.
I really have no idea why anyone would want to navigate by looking at a moving map display. If you know where you're going, you're far better off to keep your eyes on the road and use the voice prompts to get there. If you don't know where you're going - well, that's a bigger problem, and one that no navigation system will solve.
When traversing an intersection with odd angles often the voice prompt will say something like "slight right" for the road I think of as straight ahead, or vice versa. A glance at the map clears these up.
Mine did that a couple of times even in the short route on which I tried it out. I didn't have trouble understanding what was meant, because the configuration of the intersections made only one interpretation sensible. I can see how that might not be true in all cases, but I'm not sure the occasional disambiguation is worth the distraction of a visible moving map display.
I really have no idea why anyone would want to navigate by looking at a moving map display. If you know where you're going, you're far better off to keep your eyes on the road and use the voice prompts to get there. If you don't know where you're going - well, that's a bigger problem, and one that no navigation system will solve.