Backup service company Backblaze has been migrating en mass from 2TB drives to 8TB ones. The Seagate ones, at least show no difference in failure rate--1.6% per year. They must be getting a special deal on the price, because last time I looked at cost, 4TB was still the sweet spot, same as it was 2 years ago.

http://arstechnica.com/information-technology/2016/11/8tb-disks-still-looking-solid-seem-to-be-some-of-seagates-best/.