Autopilot will keep your speed stady, depending on what calss your in. So on straights your better of being under manual control, however for alot of sharp cornering i find autopilot is better because the speed is constant, and there is no need for slowdown atall.

Also another tip for mega mall, engage autopilot as you fly over the jump in the blue corridor before the spiral, then autopilot warns it will disengage just as you ave entered the spiral, but it will wait till the spiral stops until it completely disengages. You can tell by the yellow autopilot icon at the top right of the screen. When it flashes it is about to disengage, but only when the ship is level.