I don’t mind it too much, but there are a few things that bug me.
I don’t get why they seem to think that bundling it all in together is a good idea; the separate ‘maps’ and ‘nav’ worked fine. Now it seems more fiddly to get the nav up and running. I don’t know whether it actually is, but it feels like it is. Also, the way they have done ‘cards’ for the alternative routes is pretty clunky in actual use.
To me, it seems like they have tried hard to tie in the look of it to the ‘Google Now’ system, regardless of whether it works well or not.
Also, they have got rid of the zoom in/out buttons on the map, which can make moving the map around a bit tricky.
For example, the other week I was trying to follow the map to a particular street and already had one hand full. I had my phone in the other hand and scrolling around the screen was OK, but zooming in/out almost impossible as you need to use one hand to hold the phone and the other to use the zoom pinch gesturing.
It also seems to have a few bugs. When using it as a sat nav, sometimes when i turn the screen off, upon turning it back on again it displays the map, then switches to the lock screen, then remembers that lock screen is disabled and eventually re-opens the nav. When it does this, for some reason the route has disappeared from the map and you have to switch to ‘route preview’ and back to current location to get it to start showing the map again.