SO MUCH misinformation in this thread.
135i brakes WILL NOT give you any better performance, FACT.
I have not and will not track the 128, but I do for my Z4M. Stock pads are just not good. They are not meant to be driven hard.
I had trouble stopping during Autocross and refused to take them to the track.
I swapped to Super Blue and HP+ pads and I couldn't be happier. The car stops on itself.
Replace the pads and you'll be fine.
If not, have fun wasting money and finding out there is no difference.