don't think you can have a definitive answer. you know that mass centralisation is best for a low polar moment of inertia (i.e. easier to rotate about the centre of the car for a corner), but how much difference it makes will not be able to be quantified.

it's like a posche 911 or beetle in reverse really. it probably makes the braking better at the expense of turn in. i'm sure it can be mostly overcome with suitable spring/damper/ARB rates