If your in the market for a 15TB raid you should go the nas route. Your talking serious money at 15TB (trust me i know) you can stream all HD content on 100mbit connection. Mine is Gigabit all the way but the BBox is not so as far as thats concerned its a 100mbit network.
Boxee is a good product - stop bashing it.
If we all include our setup we could all help each other better
My Equipment :- Boxee Box, Cat5e, Prosafe Gigabit Switch(s), Airport Extreme, WD ShareSpace, WD MybookWorlds, Qnap-TS412, Samsung PD59D550 3D TV, Panasonic BT270 (for optical audio)