It's touch and go for me.
I find Apple Maps smoother and more fluid, functionality-wise. Seems to be more familiar as it's much like the old Maps app they made.
The new Google Maps app, in my opinion LOOKS nicer (I just like the colouring and labelling more), and is obviously much better for searching, but I find it not as fluid. For example, when I put directions in, I like to see the options visually straight away, in the new app, it seems like it gives you a list of options first, which you have to tap to see.
I value integration a lot too, so Apple Maps wins there.
Today I looked up directions on both maps, Google Maps failed by getting me to go the opposite direction once I hit a motorway, travel 10 minutes and do a U-turn and go back.
Apple Maps failed at the other end of the trip by trying to get me to drive down a set of pedestrian stairs (the destination street was split into two, separated by a walkway).
Looks like I'll have to use a combo in the mean time.
Something that annoys me in Apple Maps is how the labels for many mainstreets is fixed in a location...when zooming in on an area, sometimes the label is offscreen, which is totally worthless.
Google Maps solves this by floating the label on teh street no matter where you scroll.