What some of you against pulleys fail to understand is that the stock pulleys (not pullies BTW) generate a static parasitic loss on the motor. It is not a percentage of loss that increases with power like drivetrain loss, so the gains from going to underdrive pulleys has absolutely nothing to do with how much power the motor is making at the crank. Static parasitic loss is static parasitic loss. When you lessen that set static parasitic loss with underdrive pulleys, you will gain a specific amount of HP regardless of how much power the motor is making.
So in reality, pulleys are actually a better mod on relatively stock motors.....in regards to seat of the pants realization.