As you can see on my signature, I put a Seagate ST31000340AS 1TB HDD (FW SD1A) into my DS-106x (FW 731).
I filled it with about 700 GB of data. No issues so far, silent and perfect hibernation.
I have an external fan attached, using the thermal switch (about 30 degrees off, 40 degrees on) solution described here.
With 1 fan running, temp. is about 36 degrees under heavy use (same temp. as in the DS408).
Very satisfied so far.







