Originally Posted by gthal
Not to answer for the OP but in my experience, it is a little more difficult in the C63. Not a lot more but some. There is just so much power that you need to be gentle with throttle and be a little smoother with input. Braking and steering control, however, is very similar.
I was careful on throttle inputs as the C63 PP has a lot of torque and the rears are "skinner" than I would prefer for a car with 443 ft-lbs of torque. However, I think it turned in as well if not better than the M3 and I prefer the steering feel to the M3's over-boosted (IMO) steering. I would really like to run it again with 245 / 275s on it - which will happen soon. Brakes, I think, are better on the C63 PP, despite the weight. Stopped just as well and no fade after 20 minutes of hard lapping each time. Of course, I will still add SS lines and probably change pads for the track next time.
C63's biggest issues are heat from tranny and the rear tires. Rest is all manageable. I think on a fast track I am just as quick if not quicker in the C63; on a tight track, the M3 will likely have it as it is a bit more nimble on the edge IMO, mostly due to weight and ability to modulate throttle with wider inputs.
I will run Cayuga soon (tighter more technical track) and will report on how the C63 runs.