If you are looking to purchase hard drives, BackBlaze just released their annual report on their data center. HGST looks like they kicked up the quality control and I may have to go with them when I build my 50TB RAID this summer. Seagate's drives have a high failure rate, but they also have fewer drives in the data. The 12TB drives are hard as hell to find anyway and I hope they come down a bit this summer.