In general, I like the navigation system. I find the voice activation to be much more convenient than typing. I also really like the screen display with the appropriate lane markers, so you know which freeway lanes are valid in your direction. The forums have commented on overall improvements such as a through point and a favorites list. On top of these general feature addition, I think there needs to be a couple of quirks eliminated.
First, the navigation system likes to tell you too much information. For example, when crossing Page Mill Road near El Camino in Palo Alto it tells you to turn left when the road changes names and just keeps talking to you with gory unnecessary detail. I have muted the navigation volume completely.
My second annoyance is that it uses the freeway names instead of numbers. I have no idea what the James Lick Freeway is? We don’t use these names in Northern California.