Why should I Use a Camber?
I think a camber is useful on most planes, especially one that can be adjusted. On a smooth plane, you can adjust the camber precisely to take a fine shaving and still not leave any plane tracks from the corners of the blade. On jacks and fore planes, the camber can be increased to make planing much easier and also be able to take a heavier shaving. By adjusting to more camber, you can make your jack or fore more like they were originally intended, which was to hog off material rapidly.
Even the jointer set up with slight camber is easier to use because you can move the plane to one side or another to help in squaring the board. If you want it straight, just adjust the camber back to straight. It is so simple.