If you can i would definitely upgrade to the 13" brakes, after driving hondas for the past couple of years with their econo brakes, then getting into my car with the nice cobra brakes, i will never go back to small brakes again. Not only does it make it nice when you really need to stop, but i think that everyday driving is improved because of how much less effort is needed to stop the car. I also just put on stainless lines and i would say that they are worth it, the pedal definitely got a lil stiffer and more responsive, although i havent got a chance to really step on em and see how they preform cuz the rotors and pads are still bedding.
Leverage. In theory, you could stop your car with your own fingertips if you could put a large enough rotor on it. (i'm talking 100 foot diameter ir so) The larger the rotors, the less energy it takes to stop it from spinning.
