[300hp]

I think people are mixing up two things. Rwd will probably feel more refined and more fun in the curves. Xdrive however will get the job done but will be clumsy at it due to the additional ride height. That's what MT is saying and the "respectable" figure 8 time, which is better than the 335i rwd btw, is an objective measure of this.

Acelerometer
MT already agrees with you iro curves its right there in my initial post. I actually disagree with your assesment that the xdrive is the straight line king vs the M3, not only is the M3 quicker at 12.6s but its already going about 8mph faster at the 1/4. That's an annihilation by most standards.