The reason for the bad 60/75GXP drives were because their manufacturing sucked. This means manufacturing didn't do their job, quality didn't do their job and test didn't do their job. 10 years ago, I've worked closely with Intel and Hitachi as they supplied the parts we needed for PCs. I was deploying PCs into out manufacturing for paperless operation and including the same basic PCs, with OSWarp

, for our high end product.
Needless to say those drives sucked horribly and even then they wouldn't admit it. In new hands I haven't heard of the same issues. The Seagate 1.5/2.0 TB drives were faulty to begin with, with bad firmware. I had 100% of my 1.5/2.0 TB drives failed and all being RMAed and reflashed. But after the changes the new drives are fine.
When you get a bad HDD it's usually noticeable at he beginning when it starts to fail. Torture testing them is a good thing to do if you wanna be safe; not guarantee but safe. Honestly though, if the manufacture DID their job we wouldn't be seeing defects like that of the 60/75 GXP and the Seagates.