Using 5th gear instead of 4th doesn't mean having a greater speed during the corner. The ideal speed to take this corner is 170 kmh, I think. But if you don't reduce to 4th and take this corner at 170kmh in 5th gear, the car will not only be more stable, it will also accelerate much better out of the corner. And when I say shift early, I mean really early: shifting to 5th at 150kmh and to 6th before 200.