The sometimes poor navigation you mention with Google, how is that any different than Garmin? I've had as many if not more bad directions from Garmin than Google.
Just this last site we're at now, following Garmin with only a few miles from my destination, it led me around circles and wanted me to take roads that did not exist (yes, I keep maps updated). Very frustrating. As I was driving by myself, I pulled over and brought up Google Maps and could plainly see where I needed to go.
As anyone who uses these apps knows well, they're great tools but both can lead you astray at times.