I am using a 6Tb Western Digital WDC WD6002FFWX successfully in DNS 320L - this I understand is essentially a 128 Mb cache version of WD60EFRX (64mb). Because I could not afford 2 of these drives just now, I have it in a JBOD with a 3Tb WDC WD30EZRX, making 8312.5 GB. I know this is not really a raid, but the DNS320 acts as a server for my video collection, and the "master copy" of my files is on my PC.
Before installing I upgraded the firmware ( DLINK_DNS320L(LW).1.08b08(3.07.0420.2016))
While setting up I found that Windows 10 (x64pro is my version) would not run the version of the D-Link storage utility that came with the original CD, but the newer version D-Link Storage Utility(5.2.1.7)_01072016 was OK