I don't think it will out brake a CGT if the speed is below 100mph. @ high speed, aerodynamic drag plays a huge role, this is where the huge wing and all the aero parts of the veyron excels, but when it comes to mechanical braking.....you can not cheat physics, the lighter weight car has less energy to disipate thus should stop faster.
The Veyron lap the NS in 7:40....that shows penalties in the corners when compared to a CGT / Zonda F.
__________________
|