Primarily it is whatever is best for you. I like my Garmin 660 where I use My Route app but also I download the GPX file onto BMW connected and keep my phone in my pocket. Then I get the best of both worlds. On the GPS a bigger picture of where we are on the journey and on the BMW TFT screen very good detail for turns and rbouts. If I had to choose just one it would have to be the GPS because it is more rugged than a phone and the screen size is more suitable on a GPS. A new GPS is cheaper than a new Samsung.