MotorTrend’s latest review of the Mercedes’ CLS63 in AMG trim lists down its pros and cons. Handing is pretty much identical between the two, with reviewer Carlos Lago pointing out that the steering feels particularly nice and allows for good placement on the road. He reports that the car doesn't really feel that sporty though.
But the S guise adds a lot of power. Almost hitting 100km/h in 3.4 seconds. While not the sportiest of designs, it still packs a wallop.