So I ordered the 16tb EX2 through through Amazon and it was fulfilled by HPP Enterprises - who as luck would have it sent me the diskless version instead - and whom despite excessive correspondence refused to fulfill with the correct unit and were unnecessarily painful to deal with. So one month after they confirmed receipt of the return and I'm still awaiting their refund. Don't purchase anything which is fulfilled by HPP Enterprises as they are clearly administratively challenged or perhaps worse.
As far as the product goes I ultimately purchased directly from WD. The product is actually well designed and well built, albeit crazy slow (likely do solely to the software). I have about 5.5 TB of pics & movies and some music and this has been running several weeks and is only 80% complete on the initial backup running WD Sync with the device in raid 1. I suspect in the future it would be unnoticeable with singular files over my gig network, but this initial Sync is frustrating. In fairness I get sporadic messages about not being unable to Sync certain files and that it would re-try shortly, so maybe it hangs in between. I haven't spent much time focused on the software as backing up to a 16tb WD Duo (great device as well) gave me comfort for a backup prior to receiving this unit. I'll explore root cause at some point. Speed aside utilizing WD Sync, I like the device. The drives are quiet, the unit is not unattractive and frankly its setup was easier than other WD cloud devices I've used in the past. I am a long-term fan of WD products, but as most WD users realize their software is often not their strong suit, but from a hardware perspective its seems great, I can move files to and from it rapidly within explorer and utilize it fully as a NAS, but wish they would include some better software. I was excited to see that they now have support for PLEX and do intend to set it up in the future and will advise how that worked out in a follow up.