True that the integrity of the rotor can be compromised by the drilling, unless you buy with no drills..seems like that will solve the problem on the other hand, the sopping power on cold rotors does not depend on the rotor but does with the pads u use and their coefficient of friction, you have to be really silly to put racing pads on a street car only then you will experience what you say about having to heat the brakes.
The true advantage of big brakes is how fast they cool down and their ability to dissipate heat, seems you have never over heated your brakes in a mountain road or ona highspeed highway. I think no one will intend to get a CX9 on the track but this SUV has the ability to manage verygood performance in curvy mountain roads and highspeed highways, and in my opinion the only thing that does not catch up to that sort of driving and performace are the breaks.
correct. it is dependent on what sort of pad you are using, not the rotor itself. I like slotted rotors because the slots help keep brake dust away from the actual mating surface which is good, but they are still weaker than plain discs. To help with this problem, I pressure wash inside the rims to get all the brake dust out, as this really helps make the braking effort alot smoother and stronger.
I have Textar pads on my BMW, and even those pads require a tiny bit of warming up before full braking potential is achieved. you can feel it. for this reason I don't recommend going any more aggressive than german OEM equipment, that's plenty aggressive even for the spirited driver.
Yes, I have managed to overheat brakes before a couple times. It smelled horrible, the car barely stopped, and you need to put your brakes through one f*ck of a beating for them to even get close to overheating, so I am not too concerned about that. all you really need to prevent this is sufficient ventilation to the front rotors. that will be just fine in a mountain charge type situation where you are getting plenty of fresh cool air to the front discs. now if you are talking about Mazda's OEM brakes, the rotors are s***. I am not sure what sort of pads your CX-9 has, but I am sure it is a similar situation as with my Mazda 6, where the rotors are bad, but the pads are quite good. you will warp these rotors long, long before you feel them start to overheat. I have had lots of experience testing different brakes, from Japanese OEM to German OEM, and all I can say is that if you equip your CX-9 with some quality German brakes and still manage to somehow warp them or overheat your brakes, I will personally mail you a set of replacement rotors. one thing I really like about the Textar brakes on my BMW - while the brake dust is atrocious, you suffer from constantly cleaning your front rims for a damn good reason. the German brakes are purposely made from this dusty material that literally massages your rotors and makes them nice and shiny. this dusty material is much easier on your rotors and help them to last longer. even the most conservative driver will find a benefit in using German OEM equipment.
if you go up and look at my older post, I provided a link to a Brake thread I made where Anchorman went into detail about why he recommends German OEM. I strongly suggest you give that thread a thorough read. During my time over on the BMW forums, I was told that German OEM brakes are literally track worthy as long as you got enough ventilation and some high performance brake fluid. they are damn near impossible to overheat - I only feel them become stronger and smoother after getting some real heat into them. They feel resilient and more smooth than Mazda's OEM material.