From the Backblaze Hard Drive Reliability Stats for Q2 2015:
As far as 3TB drives go, we have replaced nearly all of our Seagate 3TB drives.
The annual failure rate graph does not paint a pretty picture for Seagate.
It is great to see companies that have to deal with hard drives on a large scale publish information like this. While I might have to make similar decision ( what hard drive to buy for a home file server ), I’ll never have 47,561 drives spinning at my house.