you are comparing apples to oranges. the p/c is used to generate heat which in turn cuts the clearcoat allowing it to blend the micro abrasives and form the shine in the clearcoat. this cant be done by hand.
so if you have swirls and haze use the p/c if your paint is perfect use the hand rub and apply poorboys black hole for dark cars and the million different waxes and glazes

here a perfect example of what the proper tool in the hands of a pro can do. this guys work is beyond genius!!
http://www.benzworld.org/forums/deta...eg-almost.html