Have four of them in the NAS just under my desk, I wouldn't have heard them click muffly or vibrate excessively when booting up now (but hardly ever reboot them).

I think they are just loud. Mine were like that too.

I've also had mine in for 2 months as a backup disk. Since the installation, there is usually a loud "WRRRÄÄÄMMM" when starting up, while the "Ä" is vibrating. I'm a bit worried whether this is the way it should be & whether it won't affect the lifetime... Otherwise, everything is OK as far as CrystalDiskInfo is concerned.