There is nothing wrong with iOS6 or even the Maps application.
In fact the new Maps application actually pinpointed my address. The old Google based map application has me living in the middle of a lake a half mile away. When it comes to map applications they ALL have their issues. Map applications are only as good as the information that is supplied. At least for me, so far, the new Map application has been very correct, and even showed alternative routes that may be quicker during certain parts of the day like rush hour. Some of the alternative routes I wasn't even aware of.
My old car had a store bought TomTom GPS unit in it and it's maps weren't 100% correct. At the time it didn't even know where my apartment complex was. The complex itself was just about a year old when I moved in. Once the map was updated the newer roads were added. My newer car has OnStar and even they can't provide directions on occasion, and when they can the route isn't necessarily the best route to take.
The new Apple Maps app works, it's not perfect, but it does work and unlike Google Maps which has been around about a decade and still can't get even my address correct, the Apple application will only improve overtime as the maps and the information in the maps is updated.