Added link to an older comment of mine that addresses the HGST/Toshiba thing. To me, it looks like newer Toshiba 3.5" models are based on Fujitsu tech (if the enclosure design is any indication). Also, Toshiba might abandon their HDD business completely. [1]
Fujitsu :( I worked at Fujitsu wholesale distributor around 1999, EVERY SINGLE drive sold between 1999-2001 died within 3 years (PB15/PB16). Those were great drives, cheap, silent, fast, and smelled great fresh from the factory due to pine sap rosin.
Allegedly Cirrus Logic controller had a manufacturing defect and died due to heat. Myself I always suspected that very peculiar and strong smelling rosin flux. PCB was drenched in it, this type of flux is usually highly activated and requires cleaning, otherwise acid will eat solder joints and copper away, especially in humid and hot environments.
[1] http://seekingalpha.com/article/3827746-seagate-western-digi...