I take it you feel they just don't bite as hard as you are expecting? I also have a similar feeling when lazily stopping. It feels like there isn't much initial bite and I do think this is associated with the electronic brake force distribution. In an effort to keep nose dive at a minimum for safety (less chance of an oversteer situation when braking AND turning due to the rear axle being loaded versus the front) and comfort reasons (flat suspension at all 4 corners), in a normal stop, the rear brakes really drag. Also one of the reasons the rears wear out so much quicker. I find that I have to use more pedal pressure (equates to a deeper pedal push) to really get the front brakes to bite. I can even modulate the pedal travel from a light lazy push where the chassis stays level to pressing another half inch or so and really feeling the front calipers bite. When the fronts bite I can really feel it and stopping power is decent.
Obviously you are not stranger to good brakes. Your CTS-V brakes hard and fast all day long. Initial bite is very good, at least in the sedan version which I've had some seat time with.
When our pads are due for service I MAY decide to go with a bit more aggressive pad compound. I've ran Hawk HPS pads for years and really like them on my play cars.
Only other option is a BBK which I really haven't seen available yet. The F30 has some OEM aftermarket options but I honestly have no idea if those packages would work based on our offsets and wheel sizes.