I have only been buying the MDD SAS drives. I bought two 13 TB on black Friday and they have been solid for last 4 months. I also bought a 16 TB SAS MDD drive and it failed after about a week and a half. I mean like completely dead, no recognition from the system. I contacted MDD and they made it good. Took about a week and half to get a replacement drive as I shipped back the defective one first. The replacement has been in place for about two weeks now. I also bought a 20 TB MDD SAS drive that I just installed today. I will check back in on this post in a few months. If you want a safer refurb option, I really like the Waterpanther DAS drives. I probably have about 6-7 of those, and only had one fail within a few weeks. Those were are SATA. I did have another one fail recently, just bad sector counts, not total failure. It was already 4.5 years old, so I figure I got what I paid for out of it. It was a 16 TB drive.