John__C

I considered them for my GTS but ended up not getting them. The standard brakes work fine and they really aren’t needed, so like you I was mainly focused on the dust benefit and their longevity. But apparently the PCCB brakes are far more prone to squealing, and that would absolutely drive me nuts so I decided it really wasn’t worth that risk.

Quadcammer

Prove it.

Ron.s

As I understand it, standard brakes stop just as fast until they get hot from extreme use. I ordered PCCB's for several reasons. The brake dust is not only on the wheels but it also sticks to the lower doors, fenders and rocker panel. After a few days my Gray wheels looked dirty even though I applied a Ceramic coating when new.
My routine was to do a wand wash of the wheels and sides after spraying the wheels with Sonax. I did this before every hand wash, a real pain. During my first hand wash I was using a light brown mitt and noticed the discoloration...it will not wash out of the mitt.. At first I thought it came from tire black but it was brake dust.
Porsche uses the rear brakes for Torque Vectoring, even with the TV differential. It's not uncommon for the rear brakes to need replaced before the fronts on some vehicles...don't know about the Cayenne.
As the PCCB's approach replacement they will be a negative factor because of the high replacement cost. I won't own the car that long. For high milers and those who keep the car a long time, it would be a consideration.