Let me just say that I love the sport button but I always wondered what changes to the car are actually made that I don't know about? As far as I can tell:
1. Stiffer steering feel
2. Modest improvement in throttle response ( by the way, would a sprint booster "double up" on the sport button in throttle response?)
3. Does dampening or spring stiffness change?
4. Does the VANOS system change in any way?
5. Do R56 Justas have a VANOS setup?

Thanks

 

The sport button increases the signal to the throttle (we have a 'drive by wire' set up vs the traditional cable connecting the foot pedal to the throttle body). It also changes the shift points if you have an automatic tranny, and gives less power assist to the steering, for that heaver steering feel. The suspension is not changed in any way. Nor is the Vanos.