Both C63 AMG models are basically the exact same sharing the 476 horsepower M177 V8 and automatic transmission. Power is not going to be an issue with this car. If the C63 sees some of the criticism from the previous model it will be regarding its heft and balance. From the video though Mercedes AMG sure looks to be putting a lot of work into getting the C63 cornering flat and transitioning well. The test drivers definitely are pushing the cars hard.
It remains to be seen what the car will weigh but the sporty character of the C63 AMG may shine the brightest it ever has with the upcoming W205 generation. It is shaping up very well.