You're experience is obviously different than mine. I have run both decks and have experienced the difference first hand also. I've run just about every brand out there and every salesman and mechanic I've ever spoken to have told me that the rear uses less HP. Everyone I've ever spoken to who do this for a living every day have also said the same thing. That's been my experience. Logically, to me, since the clippings only have to travel out the back of the deck instead of the full width of the deck, it should require less HP.