I'm a boater, so north is always up when using a marine chart. Therefore, when I am on a long trip, I use north up (fixed gps map).

When I am following local directions to a destination, and I am not familiar with the small area I am in, and the north direction is not important to me, I then us the rotating map.

Most of the time, I use the fixed map - (north up) so I can have a sense of direction.