Old as shit, I know... But Connor is correct. All else equal, a larger diameter rotor allows for greater leverage, which equates to more braking force. I'm not sure why you chose to disagree there.
As for davin's question... I don't like these rear upgrades on the B14... I hadn't heard of them until recently, but putting a 10" or 11" (or 12"?) rotor on the rear of a B14 just seems like a silly thing to me. Especially if the fronts aren't at least 13" and you're doing serious time attack work with over 500 WHP.