Some good points, hilaireg. Using the DNS-343 to hold user profiles is an unconventional use, I agree, but in this small business, this is about all we can afford to spend on network storage.
I am using a DFS share for permissioning purposes. This way, I don't need to worry about the non-windows filesystem of the DNS-343. However, I still need the active directory authentication to work, so I can prevent users from connecting to the DNS-343 by IP address and browing the root of the Volumes.
I'll be sure to update when heavy testing begins.