Problem with that is there is no such thing as 2 of the exact same rider. There are no two riders out there that are build exactly the same that have the exact same riding style or experience.
Heres the bottom line, I know for experience from riding Davids Kennedy P&P motor with the Shearer pipe that it pulls really hard. But I also know that we drag raced about a 300ft strip 6 or 8 times and me with my stock set up w K&N intake, Boyeseen 2 stage reeds and FMF pipe beat him twice. Now, means that his Kennedy build motor with VF3's and CFM air box w bigger carb beat me more times. The average win for him was between a bike length and and a bike and a half.
That is just my opinion. When buying a pipe dont just buy the pipe because you like the way it sounds or buy it because everybody has one. Buy it because it produces and does the things that you want it to.