I wish I'd done more research on Buffalo and their products, I've seen quite a few posts now relating to support, or lack their of.
Bought a Buffalo TS-4800 with the intention of creating a RAID6 array which I could expand overtime - I also made sure to buy drives which were on their compatibility list to limit any issues I might have, and to make sure everything would work.
After creating the RAID array, and populating it - I realized I was about 2TB short on space, so I went out and sourced another disk - only to discover a RAID6 array is not expandable as advertised. Fortunately I discovered this while I still had all my smaller disks to make backups (again).
I logged a support issue on the 4th of December - I was given the run around which had me continually rebuilding/recreating the array until I was eventually told that they reproduced the problem on their side and it was in-fact a bug. Whether or not they'll fix it, they can't tell me. I was told I'd get feedback in the new year. Nothing.
Contacted support again today (18th of January), again told no feedback. So I still don't know if this is even going to be fixed.
Really great when you buy a product from a company who offer very little backup, virtually no support on their own product.
You'd think considering this is a fairly significant bug on their NAS device, they'd give it some sort of priority.
I most certainly won't be buying another Buffalo product, or recommending them - its unfortunate I attempted to resolve this in December instead of returning the product before its return period lapsed.