Saturday 22nd August 2015: 5.47pm. Just rebooted into my new hard drive after cloning the old one. Because it kept dropping out during the clone and needed to be restarted, I used robocopy instead of CloneZilla, and I thought well why do just NTFS => NTFS when robocopy could do NTFS => ReFS (which can be enabled on consumer Windows using a registry value). So I went ahead and did that, and now I am running on ReFS! My only real concern will be that Linux can't currently mount ReFS drives, and FreeBSD probably won't even read a ReFS drive for many years yet. But it's a small loss given most of my music etc lives on FreeNAS nowadays.