I just bought a WD Blue 6TB HDD
So far everything operation wise (read and write), the HDD has been pretty silent which is satisfactory.
The only thing that stood out to me was whenever I unpower the HDD (shutdown, sleep or HDD going idle), there is a squeak noise (not very loud) which I have not heard from my other WD HDDs. Usually my older WD HDDs produce a click noise when it is getting unpowered.
Here’s a clip of the squeak noise (the computer case was closed in this recording): Squeak sound - Clyp