Anecdote in support of Google Maps:
I was going from South San Francisco, to the Marin County Fair on July 3rd, at 5:00 PM. this is normally about a 45 minute trip at this time of day on a sunday, even with a bit of traffic. Google Maps called it as 1 Hour 40 Minutes with traffic, the in-car GPS with traffic updates called it as an hour. We got there in 1 Hour 35 minutes.<p>I've always had a great experience with the Traffic Data in google maps - particularly in the Bay Area. Hope we get it back soon, it's worth paying for in my experience.