For me, it is less the mechanical and power components, and more the aural experience. Power bands and torque curves completely aside, there is nothing more raw or visceral than hearing an engine run through it's rev-band in a loud, brash and blaring fashion; and the S65B40 delivers this in spades. I even prefer it over the racket (which is also exhilarating) from the V-10 of the E60 M5!
If money were no object though, I would own both in a heartbeat
