SInce the last post to this thread was almost a month ago, I would suggest that anyone interested in buying Gen 4 drives, look NOW, cause the prices are dropping like rocks
to wit: I just got several 4TB WD 850x's from da Zon for $238, and also a bunch of 2TB models for less than 1/2 of that, some from da Zon and the rest direct from WD... some were for me personally, the others were for client builds/upgrades...
Note that these were purchased in the US, from the US stores, so your deals up yonder might not be as good, but still worth a look-see
And YES, these drives scream and are faster than stink on a freshly hatched pile of doggypoo