Inspect all the brakes. All four. You may not be getting full braking from both fronts requiring higher pedal preasure to stop. You will need to pull the tires off so you can get a good look at the pads. see if wear is even from side to side. Also check vacumn to the brake system. It sound like you had a qualifed installer. You may want to ask him. I am not sure about ABS electronics and if that could be an issue.
Shoot Bear When Bear In Season
2004 M3 LSB SMG II Rolling on 19s