When it comes to a fileserver, I still prefer Truenas.

I've freenas/Truenas for 10 or so years now and unraid for about 5. For the last year I've been working on migrating everything back to Truenas (scale in my case)

Some of my pain points with unraid:

• disk read speeds. (Since read is only ever happening from a single disk, it's much easier to notice bottlenecks)
• disk replacement. When a disk fails, I find the process of replacing the disk (or decideding to not replace the disk and scatter the data across the remaining disks) fairly tricky and honestly a little scary. I've had to do it twice now and it's the biggest reason I'm now only using unraid to run services but not store any important data.
• cache disks are meh. Over the years I've had 3 or 4 times where the mover just stopped, which resulted in a cache disks filling and not flushing to HDDs, which then corrupted some database or file an application was using. Like on one hand you have to use SSD cache disks to run apps or VMs since there is no way to speed up read speeds on HDDs, but on the other it just doesn't work well given enough time.

Some pros:

• Application/service hosting is still great in unraid. It's still a pain in the ass getting a VM running on Truenas scale, but with Truenas Scale you can run docker directly.

• being able to just add single disks at a time in unraid is nice (until you need to replace one...)

Anyway that's my off the top of my head reasoning. Truenas is a little more work to use overall, but I've found it much more stable