It seems like such an innocuous thing, but Maps can truly make or break a phone decision. There is no question that Android has a considerably better user experience when it comes to Maps given the lead that Google has. That being said, Apple certainly has the cash and time to devote to this and a better competitor (and more effort in OSM) means that we all win in a way. So it will be interesting to watch it play out.
One minor gripe with turn-by-turn. If I'm playing music/podcasts, I would have expected the volume to mute on the other media when driving directions are announced. Not so, it just turns into a garbled mess.
The compression on Siri kind of sucks too.