I'm currently running Freenas with ZFS.
Would be curious to see how this compares.
The one thing missing for me on FreeNAS is some kind of file search/indexing feature.
I wonder if the fact that this is Linux based will make adding something like that easier.
https://github.com/rockstor/rockstor-core/issues/484
Hmm, stats - don't know much about this topic, but I'd been keen to hear more about what's possible.
On the file indexing front, I think Recoll and Tracker/MetaTracker are the two most active projects - Recoll being the more active one. Strigi and Beagle are both discontinued.