Diff between these 2 HDDs?

11th. gen is bad - 12th. gen is fine. I don't have enough data on other gens.

Logic says that later gens are better and the problems in older gens are solved in newer gens. I hope that this is the case with Seagate drives.

I have two 1TB Seagate 7200.12 working in RAID1 with good results - and another two 1 TB each 7200.12 drives in external enclosures working fine, and another 1 TB 7200.12 drive as an additional data drive in my computer. All 7200.12 drives are great and working fine for over two years.

Yes, agree! To some extent the "Luck of the Draw" prevails! When it comes to hard drives, I keep my fingers crossed. So far, I have been lucky!

On an interesting note; I have heard people say that they will never buy a WD product, others say they will never buy a Seagate product. Pretty soon they will be out of brands!