German here and me and my wife almost exclusively use Apple Maps, mainly because it looks and feels nicer. The differences in navigation are miniscule, but if we want to really check the traffic before we start we do a quick glance at Google maps. One difference in navigation we noticed is, that Apple Maps gives some small local streets - those just one revel above "Feldwege" (agricultural/forestry roads) - more weight than they should have. They are not really "single track" (almost unheard of in Germany) but come close, with no lane delineation dashes, etc.