Yes the DBA T3 rotors are considered and improvement over oem. Atleast they are for my car and should be up until 2018 when they changed the brakes to the larger 6 piston calipers. I believe the oem rotors on the 2018 are already drilled. I think if you are going to spend the money on good pads like project mu then i would recommend just getting new rotors too. The DBA T3 4000 is what i run now and will be doing so again.The previous owner had the rear brakes done a few months before I got the car. My rear rotors are a bit grooved / have a medium amount of waveyness to them. So obviously they ran the rotors as is without turning them. Looking at the front its nice to see the rotors aren't grooved badly, but I felt them with my finger and there is still a wavey surface finish. It definitely wouldn't hurt to have them turned or replaced. Do you guys ever choose to run rotors as is when they are not smooth to the touch?
I see the DBA 4000 series Club Spec rotors are available in 2 different flavours depending on if you want slotted or drilled/slotted. Are these considered to be an improvement over OEM? The description on subiedepot.ca states "mid series enhanced performance rotor". It says they fit 2015-2017, are rotors different after 2017?