In the SF Bay area, they are generally on par depending on what features or points of interest you want to find. Some locales are shockingly different. Shenzhen China is much much better on Apple (Google and Bing show roads in the river - completely misaligned) but Shanghai is almost useless on Apple, but very detailed on Google (assuming you can even get to Google in China).

In NorCal, Apple is better in many regards than Google Maps. Better time estimates, better forestry and building designation.

For me the killer feature that makes me choose Apple Maps is “turn-by-turn” directions for Transit, including the information which exit is the best one to get to my destination.

Here in NZ I have used Apple maps as my first port of call for a few years. It’s improved a lot. On the rare occasions I’ve been led astray I’ve submitted reports and all have been followed up with fairly quickly. Driving time estimation also seem to be conservative to the point I usually arrive 5mims early which is a good thing in my opinion. I also find Apple directions does a good job of avoiding awkward turns and working out a good overall route. I also receive good and timely traffic and road closure notifications mid trip which allows me to easily reroute my journey even while en route. Another advantage is good public transit directions particually during my holiday in Europe last year. Apple is generally good enough that I don’t even have the Google Maps app anymore.

Interestingly, I find Apple Maps to be at least par, and in some cases better, in California. This is following the push they had this summer to improve their maps here.

Usually it's now better in the Bay Area.