Never been able to sum those cars up as much more than 'dumb.' It's not really a more civilized Viper or Corvette [ZR1]. It's a 'compromise' car that trades its luxury and its performance to become something that underwhelms in every way, given its price.
And while I concur that it's one of the most awesome-sounding late model cars...you can get a pretty similar noise in a C63 for a quarter of the price. Call it an unfair comparison if you want, I've just always been confused by the pricing of their high-end coupes. Lopping a couple doors off and matching the price of a 458 does not suddenly make it a Ferrari-killer. Hell, it's not even a 911 GT3 killer (which is barely over half the price).