The Apple Maps fiasco on iOS 6 needs no introduction, but it’s of interest to note that the data sources that Apple pulls map data from differ not only based on the location being viewed, but also based on where the user is viewing the data from (I don’t know how widely known this is). For example, when I’m in Hong Kong, I get data from an unknown source, but when I’m in China, I get data for the entire world provided by AutoNavi.
Ironically, the maps I get for Hong Kong are better when viewed from China than when viewed from Hong Kong itself!
Here are a few comparison shots (left side view from China/right side view from Hong Kong):
