With SAS drives, I tend to find 1 of 2 issues:
1. Fatal head crash
2. Bad sectors
I can't say that I have encountered a single case where it was a firmware issue. That said, it is bound to happen when we encountered SAS drives with damaged translators. But certainly not enough to justify the expense of PC3K SAS/SCSI.
With Seagate SCSI drives, I've just used PLSCSI to fix translator issues. Unfortunately, I don't even know if PLSCSI could be used with SAS drives too.