if his steering is really tight, there must be a reason like tire pressure too low, loose tie rods, etc.. if its just difficult while parking at low speeds, thats pretty normal. another reason to not get power steering is because a manual setup gives better road feel through the steering wheel, and the car reponds to the driver's steering input more precisely.
i would imagine that the ps would rob it of about 1-2 hp. just a guess. the main reason it robs hp is because it is an extra belt for the engine to spin.