M5 and 4S are comparable in price, the Turbo is quite a bit more. So if the M5 is beating the Turbo on the ring, then it seems to offer the best price-performance point in the market.
Of course the M5 won't hit our shores till April.
FOR SALE: 2013 ///M5 Individual Click for pics and info
Monte Carlo Blue, Platinum Full Individual Merino, Platinum Alcantara, Piano Black, Exec Pkg, Drivers assistance pkg, Bang and Olufsen, 20" wheels