Im currently using about 3tb of HDDs and looking to expand. HDD seems obsolete (for buying something Im trying to future proof with, also, drive spinning accounts for a large portion of noise in my computer) and SSD prices arent there yet. Hopefully these insanely huge advances push the lower end up.
My new one has the little rubber gaskets on the mounting screws, but the drive is mounted against a mounting sleeve (?) sort of thing. I pull a little adapter out of the HDD cage, mount the drive into that (with the rubber gaskets) and then put the adapter back into the cage. I think the noise is the adapter on cage rattle.
It doesnt happen that often (so i think it is only 1 drive doing it), so I havent bothered to look into it. But with moving parts youll always have SOME noise.
Those are $1499 retail.