These two surface changes will not create the same type of reaction. By adding polish you are allowing the ball to skid in the oil more, and then when it hits the friction the underlying surface will help it to "bite" the friction harder. Just taking the surface up to 4000 will really only create slightly added length but still the same type of smoother response to the friction on the lane.
Keep in mind however that this will be a lot more noticeable on challenge/sport patterns than it would be on a typical house shot.