Try swapping motors with your friend. I'm thinking you must have a faster motor, or maybe his drivetrain is dragging a little more than yours. I'm not trying to start a fight with ya bruddah.
I don't think that the boost feature can just "make" electricity, and these things don't have the greatest quality control happenin'.
The 1-speed Bits should be sending all the juice they can from the battery to the motor. How can the Boost Bits be sending more energy if they have the same battery?