I use regular because the book says that is what to use. I know on a car that the timing is what designates the octane and it will only burn what it is timed for. All of the octane above that is just wasted. In the old days we used to run a tank of permium through our cars to "clean" them up but with all of the additives added to the regular gas today ther is no need for that any more. So, I see no advantage to using a higher octane that the engine is tuned for.
I run 87 all the time now, started with 92 since that's all I ever ran in my bikes before. the only advantage to the premium fuel is the preium doesn't go flat near as fast; regular can go sideways in as little as 3 weeks. I fill the tank with premium and ad stabilzer when I put her to bed for the winter, that's the only time.