Got a response from OWC on the Qx2.....
The Qx2 is quieter due to being able to use a much larger fan that can spin more slowly.
Early next year we do have a new product line that will arrive offering an alternative to the QX2 which will allow independent drive mode. In the present we could only go to 4 drives with RAID and non-RAID span in order to support eSATA. Next year will have full independent mode available on 4+ bay solutions that offer the quad interfaces including when connecting via eSATA.
These solutions will require matched drive for RAID modes... But we expect to officially support them for non-RAID modes when using non-matched drives as well.
I will be waiting until next year when this comes out.
That's great to hear, as that's exactly what I'm looking for. I wonder if it'll be the same price?