The unit was working wonderfully, until about 1 month after I bought it. All 4 drives suddenly came up as "dead," and I cannot get it to recognize any other drives. I've got a call into technical support but such an error seems inexcusable for a $1k RAID!
That being said, it worked wonderfully before it died. The configuration software was relatively easy to use, too. It is a bit loud, though, and uses almost 60 Watts of power.