I currently use a Garmin Nuvi 3790t
https://buy.garmin.com/shop/shop.do?pID=63940
I got it because of a limitation of GPS on most phones, though I do know Google Maps changed to allow you to pre-download maps.
Why get a Garmin when I have my Android? Because if there is no cell data coverage, you can't navigate anywhere. With a Garmin, I'm not tied to cell towers, and there are tons of roads here in the PNW that don't have cell coverage.