Honest question: are they all noisy?
Good point, because a lot of road bikes have pretty darn noisy hubs when freewheeling, and that would bug me.
I suspect the easiest way to get an idea of a given hub is to do some YouTube searches on x hub and how they sound.
But I have no idea if it's more high end hubs or what.
And a reasonable factor to take into account for choosing hubs if you prefer a quiet hub