It's NOT just 75hp. It's 20" wheels, 14" Brembo brakes, sport seats, better suspension, standard HID headlights, and some do-dads on the body.
It's an amazing bargain at only $6-7k more for all of that.
Also remember that w/the 6.1L, you get a forged steel crank, better header-like exhaust manifolds, free-flowing exhaust, forged pistons.