I drove M5 with iron vs M6GC with CCB at COTA last year. I was blown away by the CCB. A bit of an unfair comparison as the M5 iron brakes were quite used with shimmy and grind. Nonetheless, I left the track having a hard time imagining not getting CCBs on the next M car. Agree with everyone that they make limited sense for heavy track use long term, but as a DD/HPDE car, I say go for them
It will be interesting to see how this latest gen of CCB (Porsche and BMW) hold up against track use.