If you havent gotten this months MM and FF magizne I would highly reccommend you go out and buy it. There is an awesome article in it comparing the 13" cobra conversion and Roush Brake. If you are going to spend the money on upgrading your brakes, dont go half $ss, go all the way. The roush brakes are twin piston calipers and there is no brake fade(compared to the Cobra brakes and those were upgraded as well in MM and FF)
Good luck