I would take Corvette ZR1 over every other sport car 
Well, the Zr1 is bangin---but for 3/4ths of a 599 XX, the 599 GTO is far more of a bargin...plus you smell leather not glue. I really like the limited edition Z06 that comes with ZR1 bits and hood, black rims and only in blue or orange...
Why would you buy a car with a detuned engine !!? that's f*cked up, a car company has to purposely downgrade an engine so it's not as fast as their overpriced flagship car....messed up.
They had to detune it Capt Eq, the 599 XX was a production derived "race" car---actually it was a rolling testbed. It had fans in the trunk to suck air from under the defuser to exit out where the rear lights were, it had wignlets, and F1 style Donuts covering the brakes, plus the GTO had to meet Euro and Worldwide regulations
http://www.netcarshow.com/ferrari/2010-599xx/The 599 originally had a detuned Enzo engine, they did it because the car is a "GT" or Gran Tourismo car, one that combines sport and luxury...as of 2009-2010, they took it out of that class, they had the greenlight to make it into a sports cars, thus the 599 GTO was born...and they even have a hybrid version that may come out
http://www.rpmgo.com/ferrari-599-hy-kers-concept-presents-itself-in-geneva