I've seen a lot of anecdotal reports about Apple's map quality. This is frustrating, since there's inconsistency in what one person tests vs another. I did find one attempt to quantify the accuracy of Apple's geocoder using city names in Ontario, Canada. The results aren't good: Apple returned correct data only 20% of the time. Certainly, there is much more to a map than the geocoder, but this is a pretty bad first start for Apple.
9/29/12 at 2:53pm