I've got throttlemeister, and it works very well. You can override it by twisting the grip. You twist the bar end 1/4 turn in the same direction you turn grip for power to engage, twist 1/4 turn in opposite direction to dis-engage.
If you rollback the rubber grip on the nearest the bar-end on the throttle, you will see a white plastic sleeve with a raised edge on it. You have to file that down level with the rest of the sleeve to install the throttlemeister. You unscrew the phillips screw that holds on the bar-ends, and replace it with the throttlemeister.
Throttle Miester is the best that I have used. i have not used it on the Busa though. I used it on to other bikes. the Busa is a little diffeent because of the bars. I never stay at one speed long enough anymore to use a controal. 65-65 150 65 65-180 65-65-190 65-65 120 35-35-100