Are you referring to the botched firmware ones (I think the firmware revision was SD15)?
If so, at the time (~2008) I had an HTPC with 10 1TB-1.5TB drives with 6 of 10 affected by the firmware issues. I was able to successfully flash all my drives at the time with no data loss.
i built a pc for a family friend around that time... i'd spec'd it with a different drive, but they showed it to the IT guy at their work who recommended seagate. 6 months later the drive stopped working, and it had to be shipped to the other side of the world to be reflashed
Sadly you could only flash them if they were still working, you had to ship them if they bricked. I saw the bulletin and promptly flashed all mine before failure. Big pita tho.
If so, at the time (~2008) I had an HTPC with 10 1TB-1.5TB drives with 6 of 10 affected by the firmware issues. I was able to successfully flash all my drives at the time with no data loss.