Can't say as I've noticed anything like that other than the slight vibration from the flywheel. As for speed cruising, I did a run a few months back where I held 150+ km/h for over 2 hours without any drama. Acceleration had to be reeled in as I was riding in back behind a GL1800 and a VN900, but had no issue getting up to speed or passing.
That being said, nobody would deny that the rear suspension is fairly firm, how rough are the roads where you are? I could see that causing a bit of a hum.