New Hard Drive Protocol...

[pluton]

Hard disk USB-3 Dock v. USB-3 Enclosure for SATA HD(s)? With a dock you can swap the HD(s) but there is ware on the HD connectors. Those on SATA HD(s) don't impress me. With HD enclosures you have to buy one for each drive but handling is safer, e.g. less chance of static discharge. Any thoughts on this?

I have thee 1TB HD(s) loose and will have two more as I replace them with larger HD(s) in my computer.   

Dave

The docks are relatively cheap, and thus wear on the connectors is not a big issue.  Of course, that still leaves the HDDs' connectors which are not replacable.
My operation is very small:  Only about 2 TB of both raw and finished files.  Nine external drives, with only three 'originals', the rest copies.  I prefer separate external drives at my small scale.  The so-called RAID units are great until the power supply fails and all the drive slots are dead.  In the past, when a HDD is starting to go bad, I have observed the odd behaviors/noises and had plenty of time to make a strategy for replacement.

[Bjørn Rørslett]

Redundancy is also to be extended to the drive electronics and closures ... I try to purchase a stack of hard drives estimated to last as spare drives for at least 5 years ahead in time, plus second RAID units.

RAID systems have save me from disaster several times thus I do appreciate the added security they provide, whilst at the same time being realistic in terms of expectations. RAID won't prevent your from committing grave user errors.

[MFloyd]

I have now acquired DriveDX, and it reports on my internal SSD and my external HDs.  So far so good.

Ok. Good for you. I'm operating on Sierra for a couple of weeks now., may be the error comes from there.

[Anthony]

I am on Sierra.