i have use the MC28 HRC Flywheel and stator in the past to my MC28 (i have sold it now)... As Andy correct said this part was made only to produce enough current for the PGM + Coils + RC Servo Motor and stuff like that... As for the gain that you will have will be noticible only i think on the dyno... At least i didn't feel any difference vs stock set up when i rode my bike...
But most people here don't care if they have a major gain from a part but they care most if it is a genuine HRC part (i am one of them to be honest
)... This is a big true that most of the guys here have to admit...!!!
Cheers
Michael