The only positive comment I could find:
"The M3 rear sway bar increases rear roll stiffness by reducing mass transfer forces in corners.
That should give the car crisp, quick turn-in response and reduce understeer, making the car feel more planted.
M3 anti bars give the driver the ability to rotate the car on corner entry and steer with the throttle when necessary.
It also makes the suspension (front or rear) stiffer, which will reduce the grip."