WD Drive is fine; 13% hang issue does not show up on the desktop setup for scans. Also clumsy me managed to drop two HDDs during initial second NAS setup.

Also... seems the ASUS P5N-E SLI board's chipset may be dying; while doing a data integrity run on MediaDrive, the onboard NIC cut out and never returned upon reboot. The network power light was on, however, but negotiation lights... nope.

That actually may explain the stability issues beforehand. Simply transferring the entire setup to another board (ironically an older nVidia chipset... but PROFESSIONAL) made the network work again... on the nVidia onboard NIC. The board also has a Broadcom NIC, so I opted to use that instead.

I'm back to doing data integrity checks on the MediaDrive again.