I asked this question before with no replies. Most posts relating to better rotors centre on buying aftermarket rotors as a replacement for the Subaru items, which warp.
Again, like the rear wheel bearings, this is a case of Fuji under-engineering. My suggestion is a complete transplant of rotor and calipers from a similar car that has brakes which do not warp. You would need a donor of similar weight and power, that also had 16" rims so the diameter would be similar. The problem would be the hub, would need the same spacing for the 5 studs, and might need modifying to fit other make rotors to a Subie hub.
Can any of the technical people suggest if this is feasible? Martin Rieger?, Eddycat?, Subie_qa?
The cars I would suggest having good brakes would be the Lexus coupe [2.5, 3.0 or 4.0], same weight, same speed, no warping, or a Toyota Soarer, or possibly a Nissan 300 ZX or Nissan Skyline. Once you had done the conversion, you would have a ready supply of OE pads or discs, and be no longer troubled with warping and shudder.
{I know the thought of this is going to really get to Eddycat. Putting in non Subie parts is a sacrilege, even when the original parts are not worth a s**t }
