The OP said he is using Barracuda 2 TB drives so they would not be on that list, but who knows if WD and Seagate are using the exact same disk technology or not. The description from the OP about the write speed seems to imply the possibility. We will just have to keep on top of the reports to know which ones to blacklist for poor performance.

UPDATE
Just checked on the seagate site and found that all of the Barracuda drives (both 2.5" and 3.5") say on the data sheet that they are SMR. In fact every seagate barracuda drive on that page except the 1 TB model ST1000DM004 was listed as SMR.

All others from 500 MB thru 8 TB were listed as SMR, so to avoid that tech stay away from the Seagate Barracuda line of drives.

The Barracuda Pro line OTOH all seem to be CMR drives which would imply better write performance. The IronWolf and SkyHawke lines of drives also appear to be all CMR tech.

Checking the data sheets on seagate.com tells me all of the Barracuda line of drives are using the SMR tech on the disks. Reads will be mostly fine as will small writes, but extended writes will suffer greatly. The drive technology is fighting you. The more data on the drive the slower the writes will become.

The BarraCuda Pro, IronWolf, and SkyHawke lines of drives use the CMR tech and do not seem to suffer from the write slowdowns.

Yes they sell two different models, even got the nerve to tout the CMR as some kind of feature, neglecting to say the reason they do it that is because of the law suits. That sued them for silently changing the methods used for recording to the disks.

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Thanks to all for your advice. Indeed, these are indeed the same hated drives as kilgoretrout got at microcenter and promptly returned, but they seem to do very well in a 3 drive raid array, getting writes of ~325 MB/s and reads of 450 MB/s. For what I have planned, I doubt the limitations of SMR will be an issue. They're only for media and storing backups, but in the future, and I definitely won't be writing the warranty assumption of 54 TB/year to them.

I tend to be on the optimistic side. We'll see how this goes.

In a normal (home) environment, no reason to think they won't work satisfactorily. Might run into the same problem you initially reported if you have to resynch or reshape at some point.

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Not entirely nuts. It helps you burn them in. Make sure all the bits are adjustable. I often dd all zeros to a new drive then cmp the drive to zero to see if it actually wrote it out. Although some drives come as all zeros from the factory. At a minimum that'll (if only in theory) help to recover data as unused portions of the disks will be zeroes. It could also help identify a questionable drive early if doing a full write of the entire disk makes it get very hot (relative to other like disks). Or noisy if spinning rust.

But I have plenty of PIs and such to do those "duration" things which keeps my main machines free for other uses. I mean I already waited a few weeks to get them from amazon, another couple days to set them up isn't unreasonable IMO. For home use anyway. For a corporation where your disks already failed and you needed those replacements days before you actually ordered them / got the order budgeted / approved. That's a different scenario.

Accidental repost. can't find a delete post button.