As another point of comparison Apple Maps works very well in China whereas Google Maps is completely broken (even if you have the data offline the GPS location is usually wrong). Apple have obviously put a lot of focus on making it work there.
That's a stupid Chinese restriction because Chinese mapping data uses GCJ-2 instead of the standard WGS 84 datum. If the Chinese government were to give Google the license to use their datum, Google's map location issue would be gone. (Though POI would still be a problem.)
