Pros: Seems better constructed than the single drive BlacX.

Cons: Very misleading specs would lead you to believe that one connection (eSATA or USB 2.0) enables both drives. That is true of USB 2.0, but if your motherboard does not support port multiply, the eSATA connection will read only the first of the two drives. This is not in the documentation, specs or advertisement. I discovered it after purchase while searching their site for an explanation as to how to get both drives to work. It was a footnote to their three question FAQ on this unit. So, make sure you're mobo will support port multiply if you want to use the eSATA connection.

Overall Review: I bought this to replace a single drive BlacX unit. Unbelievably, after I decided to get the Duet unit but before I ordered it, the single unit quit working (2 years of use).