I've received this e-mail as well from BMW. Is this similar to a chip, like a JB?
I recall reading on most of these that BMW lists the peak torque added at very high RPMs. My guess is that going from 300 lbs-ft of torque to 317 or even 332 will hardly make a difference in every day driving, unless these are added on very early in the torque curve.
Even then, with the massive amount of torque the car has, I doubt most people under regular driving conditions would even notice 30 lbs-ft added, even at low RPMs.