You are reading the data wrong. The 4tb have 5k hours for 400 drives while the others have order of magnitude more spin time. The other type of 4tb have a sampl

You are reading the data wrong. The 4tb have 5k hours for 400 drives while the others have order of magnitude more spin time. The other type of 4tb have a sample size too small to conclude anything (a single bad batch is possible). Given that the drive failure risk is a curve over time, you need more data. Drives are not reliable when new or very old, but usually ok in between. That being said, I will never ever buy a Seagate HDD again. They joined Maxtor in my blacklist a long time ago. I lost every single one I ever bought (and RMAed) within a year.