The first look at the inside

under cable 3 & 4 looks to be inductive filtering for th power supply, the other part that is a sort of darkish round object looks to be a cheap timing unit for the R/W controller, there are more stable designs available. On the + side, you can't go wrong with ARM.

"Using FreeNAS in an older machine may work out quite nicely. "

FreeNAS has some performance issues when used with SAMBA. I wound up using Linux on an onld PIII with a cheap SATA RAID card.

I only wish it was that simple.

There a three Realtek chips on the board. You are correct that one of those is the Gigabit Ethernet switch, but the other two add the ability to control the device using a Web browser. All three chips work together.