My wife has a Tom Tom that my mother-in-law gave her and I hate it.
In the city it will actually have you turn and drive one block east, then turn and go one block north, then have you turn and go one block west to get where you would have been if you had gone one block straight ahead in the first place. I has also taken her miles out of the way on trips. She had to call me once to get her back to the right highway exit to keep from driving 25 - 30 miles father west to pick the same interstate hwy.