Purchased my '13 C63 AMG with the P31 AMG Development Package and Carbon Fiber option over labor day weekend.
In a word, this car is..ridiculous.
Cross shopped the CTS-V / Audi S5 / BMW M3.
If you are looking for the best handling car with the best driving dynamics to track on the weekend - buy the M3.
This car has intoxicating torque and the exhaust is a symphony. If you're looking for the equivalent of a German muscle car at a decent price point that will make you smile during your DD time - then consider this car.