So here's the thing with massive individual drives. Assuming you're buying multiples for redundancy (say 4 for a 3+parity stripe), you'll probably come out ahead cost wise over a similar total capacity with "normal" sized 12TB drives.

But if one of those drives fail, assuming your consumption is around 60-75%, the rebuild time is going to be massive.

For comparison, I just upgraded from 6TB drives in my Synology 5-bay. It was pushing 90% utilization. Doing a drive by drive swap, waiting for the parity to rebuild as I replaced each one with a 10TB drive - it was the better part of 5 days.

If you are thinking of using it as a standalone drive (no redundancy), your back up plans better be solid, testable, and off to a different system (no relying on time shift to the same drive).

As long as you have parity drives, not a big deal. Unraid wasn't designed to only run on enterprise-grade drives. I'm sure their forums have guidance on when to go form a single to dual parity drives. I do know that your parity drive has to be the biggest size drive, so if none of your existing ones are 24TB, you'd be buying at least two of these to actually benefit much form an upgrade.

I run unraid with 30 disks. Most are in the 18 to 22tb range. It works pretty well, but parity rebuilds take 4 days or so when I replace a disk. Much longer if I'm writing large amounts of data as well.

Biggest issue is that your parity disks must always be your largest disks. So you'd need 2 of these to make it worth it (if your only using a single disk for parity.) Which makes jumping into them pricey.