I've grown to prefer Apple Maps over Google Maps because it's turn-by-turn driving instructions are more pro-active. Frequently the instructions from Google Maps come 5 to 10 seconds too late, whereas Apple Maps is saying things like "go past this light, but then at the next one turn left" right on time.
There is, however, one area I'm not sure of it with. Traffic. I can look at Google Maps and see that it's always got its eye on the traffic situation, whereas I can't always tell with Apple Maps. But then, I'm not often driving in high traffic areas, so I'm not sure.
Has anyone here done a good comparison of the two when it comes to getting you around or through high traffic?