So they're sticking with the NA 6.2 motor. It's tuned to produce more hp and torque. It has a locking diff and the MCT. How is this going to be any better performance-wise than a regular C63 (coupe or sedan) with the AMG performance package (that also has some of the SLS M159 internals: pistons, connecting rods, and crankshaft), and can be easily aftermarket tuned to further increase hp and torque? A 44 lb loss in weight isn't going to make this any quicker than a tuned C63 coupe and especially one with the optional performance package (and it also has the MCT, too.)
This appears to be more of a cosmetic package which is a bit disappointing. I guess we'll have to wait and see what else it has to offer that isn't already obtainable with the non-BS C63 coupe.