Many of the people you are polling will argue that aftermarket mufflers don't really drone and caster camber metal-on-metal plates don't make noise, either.
Also, all-metal motor mounts are reasonable for street use, and removing all the sound-deadening insulation is worthwhile & doesn't really affect streetability.
So take this advice with not a grain of salt---a whole shaker full.
Mine's still in place & so's my STB.