I think there are a lot of factors in play. But to me that much excess weight would bog the car down coming out of corners relative to a car which is 150g lighter.

At windsor or ACT (carpet) i have run my car up close to that kind of weight.

But i think you will also find it depends on how you weight your car.

Say putting all that weight in the bumper may help put more weight down on the rear tyres but to me it would also cause the rear end to swing out violently through hard turns.

Also more grip may make a car easier to drive but too much grip is often slower. Generally speaking a fast driver will often want their car to rotate. Such that the rear end is on the edge of letting go.