16 Terabytes and Nothing On
Drobo has brought back its four-bay BeyondRAID storage solution, upgraded with USB 3, better Time Machine functionality, and faster rebuilds -- at a "budget" price of $349. The lack of Thunderbolt is kind of a bummer, because you'll need to spend twice as much money for the faster connectivity and just one extra drive bay. If it had Thunderbolt, or even just an SSD slot like it big brother, the 5D, this would be a no-brainer upgrade decision for me.
But my second-gen Drobo has been going strong for four years now holding my iTunes library, and I couldn't be happier with it. If you have big backup or storage needs, and are good with USB 3 speeds, this ought to suit you just fine.