Facelift A good read of why Carbon brakes aren’t always the best choice.

[T-800]

Scroll down past the sales patter for a good write up about brake discs.

https://www.essexparts.com/essex-designed-ap-racing-2-piece-competition-j-hook-disc-pair372-RS3

 

[Beebee-one]

A great article on the functionality and differences between materials and how you use them.
In my opinion, AP are the best option for upgrading brakes, I have used them on previous cars which I tracked frequently and found them to be totally reliable if you set them up correctly. I am currently running the Alcon/Revo disc upgrade with the OEM calipers and Ferodo pads, it's a great step up over the OEM discs and pads for fast road and some moderate track use, but the ultimate upgrade is the AP options with the RadiCal calipers if you can afford it.