I always perfer FOSS whenever possible.
I figure if someone out there is working on a project and wants me to use it, I owe it to them to at least give it a shot.
Occasionally, the proprietary stuff is the only option. And occasionally-occasionally that company isn’t worth supporting or the price is unreasonable or more than I could afford. In which case, perhaps some seas are sailed.
It’s not hard on Debian
https://wiki.debian.org/ZFS