Well as a non pro level driver I can tell you that the IB vs GP debate can be compared to the Panasonic vs Sanyo debate from years ago. To me the IB's resemble the Panasonic's....Super punch out of the gate and fall off slightly. Now I said slightly dont over react. The GP's are like the Sanyo's, linear through the entire run. I have thought more about why the IB's feel like they fall off slightly. Could it possibly be that they are putting out too much power for our motors to handle?(motor heats up motor goes slower) Is it the motor or the battery that actually is falling off slighly?