We just crossed the Atlantic and never actually turned our Garmin GPS on. Just used an iPhone and iPad with iNavX and Navionics apps the entire crossing. The Garmin is now relegated to an emergency backup if all 3 of our iThings stop working.
I created a route from Annapolis to Cape May via the C&D Canal to figure out distance for planning and for DTG given the fact the route was far from a straight line. Once we cleared Delaware Bay though it was strictly go to waypoints.
I can only see myself using the route function for ICW type moment. In more open water, GoTo works just fine and takes a lot less time.