What a professional driver can do with a car with lots of power and a sketchy suspension vs. what joe average can do is a very large difference. Though I would be curious to see more different track times. That one may well favor straight line performance (don’t know myself).
Most of the video reviews and comparisons of the new Mustangs point out that while the M3 and other (high dollar) independant rear suspension cars are more sedate and better behaved on the corners, the torque and power range of the Mustangs pull it ahead in the long run.
You have to admit that Ford has hit it out of the park with the new Mustang 6 and 8 engines as well as taming the solid rear axle.