All well and good, but Drobo the company is a horrific entity that preys on people using FUD and then exists only to force you to pay them for service. Case in point: I got a 5D as a birthday present around June 2013. It took me a couple of months to get it set up, but that was far from uneventful. As I recall, I ended up having to buy three new drives, even though the existing lot were all on their supposed support list. Why? Who knows, the Drobo would find errors that didn't exist in SMART data, never appeared on any other drive, but okay, fine, perhaps these (then) six-month old drives were from a faulty batch. The Mac software would crash. All the time. And when it crashed, if you connected/disconnected ANYTHING from USB, the computer would lock up with its fans spinning at maximum for 15-30 seconds. I would have conversations like this with their phone support:
Drobo: "Install the latest version!"
Me: "What, your software just updated and force restarted yesterday."
Drobo: "No we have a new one!"
Me: "Oh, I see you do." Install, reboot, crash.
Drobo: "Oh we know the issue, it'll be fixed next release!"
Me: "OK"
A week goes by, another release, go to step 1.
Finally I stopped using the Drobo software after configuring the piece of crap, and at least the crashes and constant reboots went away. Come March 2014, and I wake up to the Drobo flashing only red lights. I call support only to be told "oh no, now it's $399 for you to speak to one of our agents since your warranty is up," which lead me to send in the receipt, only to be told they now only offer 90-day phone support despite what was promised, and that I could email them. So I did. You can imagine how this went:
April 8: first report
April 10: automated response
April 13: RMA started, but first, they want me to do some troubleshooting.
April 15: steps arrive.
April 15: I respond.
April 22: they reply with one more question and a suggestion to update.
April 22: I reply.
May 2: they reply with one more question and a suggestion to update.
May 2: I beg them to just send all the goddamned questions at once.
May 10: notification my standard warranty is expiring.
May 12: blank email.
May 12: I ask them what's the status.
May 27: automatic case closure notification since they've not heard from me in three weeks.
May 27: "Wtf no."
June 12: email that says my warranty has expired and they want several hundred dollars for an extended warranty to replace it.
That's right, these scumbags ran out the warranty over 14 weeks rather than replace their defective product. I was so glad to hear when they went under, but some idiot seems to have bailed them out. I ended up buying a 4-bay to get my data off the device and then got rid of them, because "BeyondRaid(™,R,C)" can't be recovered from using anything else.
So by all means, if you want to buy it, then buy it - just don't use it for data storage. Better yet, buy any 4-bay case and use OpenZFS's zpools. It's actually recoverable, the community gives better free support than Drobo ever did, it's free and it's better than Drobo's crap software because it protects you from bitrot.
TL;DR: Drobo is a scumbag company that makes unstable and crashy products, retroactively changed their warranty and demanded money for their failures, before eventually running out the warranty. Use ZFS instead.