Perhaps the most noticeable difference betweeen Apple’s old and new maps is all of the vegetation detail Apple has added:

And now, without announcement, Google is adding it too:

The Northeast is noticeably more green:

And so are other parts of the U.S., like Northern California:

And the upper Midwest:

When the maps are zoomed in, Apple’s vegetation tends to be more detailed than Google’s:

And Apple’s goes all the way to the last zoom—but Google’s abruptly stops at z13:

But when the maps are zoomed out, Google’s vegetation often looks more detailed than Apple’s:

Either way, this detail sometimes makes the maps more difficult to scan. Here’s Apple Maps before and after the vegetation was added—notice how much harder it is to see the map’s roads:

And here’s Google Maps:

With all of the added vegetation, there’s less contrast than before—and it’s harder to follow the roads or scan the cities.

UPDATE #1 | February 2020

In the time since this was published, Google has made changes to improve text legibility:

UPDATE #2 | August 2020

In August 2020, Google added even more landcover data to Google Maps: