TET930

I thinking what is going on. During braking from 60 to 40 ( in higher speed it is much more less) I feel vibration on steering wheel and if my TT will be with steel rotors it is clear what it is but with PCCB? Any idea? maybe it is not rotors?
It is possible that PCCB could bend? (I don't thin so!)
Otherwise braking is perfect but this vibration is only one thing that I like to remove.

993GT

sounds like a bad wheel bearing or suspension bushing, shouldn't have any shakes/vibrations with PCCB, steel rotors could warp and cause vibrations or if were very hot and held with brakes on at a stop then could have forced a pad material transfer onto the rotor...check wheel bearing suspension components and tires for defects/wear

Misplacedyankee

Maybe try a break in procedure. I am sure you can google how to do that correctly, but basically brake very hard several times from high speeds and see if it goes away. My PCCBs will "honk" if they haven't been used much. What I do now is brake hard several times to heat them up and glaze them a bit and have no issues for a while after that. Just a thought before you get too deep into diagnosis.