Been running an 8 drive array for nearly 5 years now myself and never once had an issue through 3 PCs and 3 different operating systems. What was your issue?
With utmost respect: this isn't a super valuable data point. A "production deployment" with lots of users and/or workloads will see issues you will never encounter in a moderate setting.
FWIW, I use FreeNAS in a similar small but diverse setting with nary a problem, but when I sat it up for a 30+ organization, issue arose that I hadn't expected (not data loss, but usability and performance issues).
ZFS has definitely been used in very large production deployments in a variety of scenarios for well over a decade. The question seems reasonable given that history. ZFS isn't some toy filesystem hacked together over a weekend.
