This sums it up for me (from
https://www.tenforums.com/drivers-h...le-possibly-corrupt-metadata-please-help.html):
From what I've seen of people with problems with storage spaces, they end up vowing never to use it again.
Absolutely essential is to ensure you have a backup, and to continuously monitor the disks for signs of degradation. Sadly it seems you were doing neither.
People just don't monitor their hardware in the way that you would in a work environment.
When I played with Storage Spaces a few years ago, I never lost any data, but only because I didn't keep it for long as I very soon felt it was overly complicated, completely opaque ("what is going on?" which made me very nervous), quite limiting depending on the decisions that you made when you set it up (I had to re-do things a couple of times, no big deal, but if it impacts you a couple of years down the line and you can't change it because you don't have enough spare capacity, you're going to be pretty annoyed), and performance was absolutely abysmal. I'd forgotten about "columns" but was reminded just now when I went to have a quick refresher of why I disliked it so much (you have to get the number of columns right at creation point and you can't change it). Adding new drives doesn't give you better performance as performance is linked to the number of columns.
In general, RAID (hardware or software) is not risk-free, PARTICULARLY in an un-supported environment, i.e. when you aren't paying someone to support you when things go wrong. Hardware RAID is fairly simple and well-understood, but you are tied to the hardware controller, and if that dies, and you don't have support, and you can't find an exact replacement, then you've effectively lost all of your data (a lot of cheaper RAID cards are doing the RAID via a software driver, so avoid those as well). Software RAID is a much more complex beast, and while there are known mature implementations (a list that you will never find Storage Spaces on), you are still tied to a complex set of interacting dependencies (OS version, RAID software version, disk controller model/driver/firmware, drive model/firmware/capacity/speed, etc.) -- get the "right" set of dependencies wrong, and you lose your data: "oh, didn't you know that if you use the RocketSATA3000 controller with 12TB WD Red drives you lose all your data after 100 hours?" type of thing. Just like you discovered with that Registry setting that "fixed" the problem.
For playing with and learning about RAID, or for hosting a bunch of stuff that you don't mind losing: go for it. As a method of storing valuable data: please don't do that.
As a pretty universal rule I advocate AGAINST RAID in the home environment, and of all known (to me) RAID implementations, I would rate Storage Spaces close to the bottom in terms of complexity and performance.
I consider Synology to be an exception to this rule, for one simple reason: you are SUPPORTED by Synology who will help you get your data back (and have many years of experience doing this, so I'm reasonably confident in their success rate or we would know about it). Synology devices also have very good hardware monitoring, so the second there was something wrong with a drive, you would know about it.
I'd be interested to see the links/studies you used to decide that it was better than HW RAID.