BTRFS is in a perpetual beta because the developer(s) haven't been able to iron out all the bugs. Not even the filesystem format has stabilized yet. (Open)ZFS,

BTRFS is in a perpetual beta because the developer(s) haven't been able to iron out all the bugs. Not even the filesystem format has stabilized yet. (Open)ZFS, on the other hand, has ten years of enterprise production use under its belt. And versioned filesystem and feature flags, so the latest OpenZFS can read all its previous versions (and ignore unknown feature flags) without breaking backward compatibility. Like the other commenter stated, it has no equal right now. Closest thing to ZFS, conceptually, is the Oracle automatic storage management (ASM). While ASM is available on Windows, ZFS is not, but FUSE might actually let you run it. Might.