I love copy-on-write file systems and ZFS always loved me back. With ReFS story was a bit more tangled as something always stood between us. Be it requirement for registry hacks, be it idiotic decision that integrity streams are not supported for virtual disks, be it lack of boot support (even when using it only for data), or be it just general slowness and opaqueness of its development. Despite all those issues, I have used it for all data on my Windows computers since 2015.
I'll shed a tear while formatting my disk to NTFS; and dream of ZFS...
PS: No, even more than 5 years of its creation, ReFS is still not bootable.
PPS: Yes, I am aware that read/write will still be supported even in Windows 10 Home. Not good enough for me.