[RndTbl] FreeBSD ZFS vs. OpenSolaris ZFS?

I see that the latest FreeBSD release, 7.0, is supposed to support Sun's ZFS file system. I was wondering if you were to (for example) install FreeBSD on disk A using FreeBSD's 'normal' file system (UFS? UFS2? FFS? I haven't been following BSD file systems), and then set up disks B and C as a mirrored ZFS pool, could you later install OpenSolaris on disk A (replacing FreeBSD) and have it read the existing ZFS stuff on disks B and C? Or install OpenSolaris first, then FreeBSD later?

As a bonus question, would anyone care to comment as to whether FreeBSD 7.0 or OpenSolaris (any version) are stable/reliable enough for a (home) production file server, specifically with respect to the ZFS support?