20 years ago I saw Amsoil as snake oil but seem to be running it today. Yes, MC specific. What I can say is the tranny in the Fizzer loves it. Power is super smooth and it's an annual changing with Wix filters.
I encourage the Mobil1 users to give it a shot and offer feedback as I drained that product out with 1,800 miles on the clock when I was riding 5k mi a year to find a night and day difference in engine smoothness, gear clunkiness reduction, and probably picked up like 27.83hp!! Blah