Thank you
freakzy and
lcoughey and thank you to all the pollers
You answers are both useful and complementary.
When I asked this question I supposed that not many PROs would have answer, this is really a strange behavior, yes, because I don't ask how to dive in their use

Cases amount is raised among these last two years, and so I'd like to keep some additional cases in my laboratory instead than forwarding always to third party DR companies. Some cases in Seagate and WD "
sounds" like firmware issues, sometime they are, sometime they are not. Some time they are drives with many bad sectors, so really unusable and needed to be cloned.
Reading about PC3K, I understand that provides some advanced cloning features. This sounds that in average (bad firmware drives and drives to be cloned), it would be smarter to buy the PC3K or do I miss something?
I'm fighting against this point: DDI provides cloning only, PC3K firware and cloning (maybe not sophisticated like DDI): don't this sounds like PC3K could provide more recoveries than DDI (meant without opening the drive)?
Thank you for your replies and sorry for this delayed one
Andrew