I don't have pics of mine plus I did it at the same time I installed my exhaust, so I wasn't able to do any before and after test with the airbox alone. From what I understand, it takes away some torque down bottom (sub 3000 RPM ... how often are you in that range) but gives you an extra 2 - 4 horses after that.
, then click "gsx1300r modifications", scroll down and click "airbox modification", and read up. It has a pretty good description on how to do it, what it does, and what to expect.
