A bit of an afterthought, but when Motor Trend raced the M3 against a Mustang GT, I believe the M3 had the competition pack as well. So it's worse with this option, which tends to invalidate that test.
I drove a Mustang GT with the Brembo brake package. It was fast, but the most awful riding car I have ever driven. If you drove over a pencil it would shake your teeth, that bad and I am not exaggerating.