1. Loaded my DNS-323 NAS firmware using FW version 1.10b7 (beta).
2. Installed two WD20EARS (Advanced Format drives - ie: 4k sectors).
3. Formatted both - took awhile but it did finish and then asked for a restart.
4. Configured for RAID 1 - took awhile (about half-an-hour) but it did finish.
5. Added users and folders and setup the access permissions - worked fine.
6. Used the built-in "Scheduled Download" to move my videos / movies from other servers to my DNS-323.
7. Worked like a charm and ran like the hammers of hell - glad I've got gig-e interconnects.
8. The updated AV server (DLNA 1.5 compatible) works like charm - no problem streaming videos to my DLNA compliant media receivers from my DNS-323.
9. Initial testing shows that I can get transfer speeds of 12 - 16 Mbytes/sec using gig-e interconnects and writing to my DNS-323 by pushing files from my windows box.
Looks like D-link has got this box working sensibly with Advanced Format Drives. Now WD rates the WD20EARS at 110 Mbytes/sec sustained transfer rate. The SATA interface for this drive is rated at 3 Gbits/sec and that rate should easily sustain full speed transfer to the drive. I've got gig-e connections routed through the LAN side of a D-link DGL-4500 high-end router. Gig-e connections should handle about 100 to 110 Mbytes/sec sustained (assuming little else is happening on the wire). The windows box I was using to push the test files was showing about 15% CPU utilization and was not doing anything else - so it was not a bottleneck. So it would appear that the DNS-323 hardware / firmware was the bottleneck in this test (probably it's processor speed, but also maybe the way it handles the 4K sectors with RAID turned on). So it looks like the DNS-323 tops out at about 12-16 MBytes/sec transfer rate with WD AFT drives.
All in all, I am very satisfied. I hope D-link releases an official (non-beta) release of the firmware soon.