"Power". What is "power"

The term is so general, that almost any statement about "making" it, would be true. Unfortunately, many people fall for the "horsepower" number, which means virtually nothing in the U.S.
What do you do, here, with 125 horsepower at 9,000 rpm, when your roadspeed rarely exceeds 90 mph
In Germany, on the Autobahn, trying to sustain a speed of 125 mph over a longer distance on a bike without fairing, yes, horsepower matters.
That's what exhausts like the Schüle are designed for. In the U.S., they are borderline waste of money. If you take the $3,000.- and invest it into some other measures to boost the torque between 3,000 and 7,000 rpm, you get more "bang for the buck".