My car originally had 14" rotors but Forgeline shaved the pad and instead of rehooping my wheels, I opted for a 13" rotor. The larger rotor is an advantage. It's hard to compare as I went from a 255mm 200 treadwear to a 275mm 100 treadwear at that time.
I rode in Casanovas car and he has small rotors and his car stops REALLY well.
Pad compound and pedal effort are also big factors. My car has a 1" master and manual brakes. At the end of the day at Buttonwillow, I had finally started treating my brakes like I was stomping on a bug. You have to be very agressive and it's hard to get used to after any daily driver. My car would benefit from going back to the 7/8 master or power brakes. Especially in autocross. The 1" was a bandaid for our best buddy, brake pad knockback.