I tend to agree that OEM pads are safe bet, especially when it comes to Mazdas. I've worked with Japanese engineers and was very impressed with their testing thoroughness. That being said, I must also mention that I am running Hawk HP pads on my MX5. They are a bit more aggressive than OEM but sometimes make a slight squealing sound that is low-key and for short duration. When the rotors need replacing, I will get J-hook style slotted versions.
I've tried a few variations of rotors and pads when designing rotors, back 5 years ago, so preferences were developed during that period.