For long distance trips, I much prefer the Garmin with a larger screen, but especially the extra info. it will display. I also prefer to keep my phone free for phone use. I also like how it is easy on a Garmin (or similar device) to look for things along your route like gas stations, food, etc. Google maps will not allow this. Google Maps does have much better traffic, so when navigating a big city, my wife generally has a phone with Google Maps running in addition to the paper atlas she keeps handy. Garmin or Google can send you in a bad place at times, especially in remote areas where road types are generally less well defined or there are more "roads" in the database that aren't really roads generally traveled (especially with an RV).
Around home when driving around for business or going to new places, I just use my phone.
