My wife after she got her new job about 5 years back ran out and bought a 300 Garman unit (About the size of a loaf of bread) and kept telling me how good it was. So about a month later her workplace was shutdown for a long weekend and we went for a trip to Cleveland. She wanted to show me how well the Garmin worked so she entered the Address of our Hotel and off we went.
The Garmin unit performed well for awhile until we hit a detour and then it started saying "recalculating" over and over. (She had no idea how to adjust the unit for a detour AND she left the instruction book at home...) I kept a running commentary on how nice it was to hear "Recalculating" over and over for 15 minutes straight.
Finally we get near the hotel (according to the Garmin) after it had adjusted to the new route it led us to a dead end road under an overpass on the highway and declared we had arrived at our destination. The only thing near is for a mile in any direction was an abandoned factory. She reached over and quietly turned off the unit and called the Hotel for directions... I laughed all the way to the hotel...
LOL...I still consult a map when traveling somewhere.