I have a 320 and 750. Its too bad you cannot configure part of a drive to be RAID 1 and the rest not.
So Im upgrading to 2 x 1 TB.
To do this I pulled out the 320, put in the first 1 TB, then entered a scheduled local copy and then pressed the option to do it now. There is 450 GB of data to copy, and its been running for 6 hours and still going....
Why is a copy from one HD to the other taking so long?