This is the ultimate RAID1/Mirrored data redundant storage solution! The only thing it does not have is eSATA. You can buy the case by itself or with a combo of WD GreenPower or Raptor drives. If you already have 2 identical harddrives, it will cost less than $150 for the case. I really want 2 of the 2TB+2TB solutions, which are about $680 each. Buy from OWC.