[qab5b]

If you are really worried about more unsprung weight, then you could have the rotors cross drilled or slotted. If you are looking at the whole scheme of things, then the amount of unsprung weight gained and its affect on handling will not make up for increased braking power, and the effect in has on lap times. Brakes are very key to turning faster lap times.

Or you could get some really cool carbon brake rotors like they use in Formula 1, they only take 6 months to make.

Also, one should take into account the availability of brake pad compounds: some caliper/rotor setups have a wide variety of street and race pads available, while others don't.