The main aftermarket satnav products are from Garmin and TomTom - and in-car systems tend to either license their tech or use NavTeq/HERE. Even Apple Maps bootstrapped off TomTom and still largely just aggregates from other sources.

I use iOS, but I very much prefer using Google Maps to Apple Maps: mainly for the Google Account integration, and it feels like they provide more information (shop/restaurant hours, street-view) even though Apple Maps provides almost the same level of detail. On my desktop I use a Google Maps and the map design is the same so familiarity helps, whereas Apple Maps is strictly off-limits for Windows and Linux users.

Given that Apple and Microsoft are no-longer competing in the mobile space (MSFT finally admitted Windows Phone's failure earlier this year) maybe we can see Apple choosing MSFT/Bing services over Google? Apple could save a lot of money by switching to Bing Maps, and with a re-skin no-one would notice!