I have both an Android and Iphone and I have used both applications. The Google Maps app is a far superior piece of software because it is more intuitive. The Apple Maps app seems to be limited in the amount of data and areas it covers accurately. In addition, most of us are well familiar with Google Maps because we use it on a regular basis during normal Google internet searches. Hands down, Google Maps App is far better.
Have you tried Apple maps? It works OK, but just isn't that great. Google spent many, many years gathering data, testing programs and fixing bugs. When Apple decided it wanted to get into the maps game, it didn't have those decades of research behind it. Google does. And Google can use those years of information to make a great maps app. Apple has years of development ahead of it to even come close. Just try to navigate an unknown area using both Apple and Google maps. You'll find that 90% of the time Google out performs Apple. That last 10% of the time, they both perform equally.
Google Maps has been around much longer than Apple and has a simple interface with many filtering options. You can access an easy street view to get a sense of your bearings. It's also free to access, and you don't need an Apple product to download the app. Google is free for all.
Google Maps is better because they have been around for much time than Apple Maps. Also, Google maps is easier to navigate to and has the street view option, which can help you find the location you are looking for in a much easier way. I believe google maps also update much often.