The post is interesting, but very generalized. Back in the day when all Brembo jobber discs came from Italy- it was easy to tell the quality from junk. Now, Brembo itself is junk for the most part- in the aftermarket area, as the production has shifted to almost every 3rd world country.
Most Brembos we see in NA come from Mexico or Brazil- not Italy. The quality is just not the same. Even if the rotor has tell tale signs of being Brembo , as indicated in this thread- it guarantees nothing!
In addition, Chinese rotors have come a long way and when you pay the right price, you can find plenty of good stuff out there- which isn't Brembo.
Mountain discs- still Japanese and among the best, Zimmerman and Sebro- great German discs, as well as ATE. Pilenga and Kiriu also solid choices.
Thats said, you would be surprised to know how many light weight track cars I have supplied cheapo rotors for the track- and they work!!
Brembo- not what it used to be......