No, to be fair I use it for everything except root (which I prefer to backup as IaC, not that I wouldn't use ZFS, it's just not default so requires more effort). I use ZFS datasets to back everything except the OS, including DBs which has been the most satisfying aspect of using ZFS (being able to snapshot live DBs together with all other relevant state rather than a as a separate replication process).

While I can't comment on using it for root, I can say for other use, the only annoyance I have is compiling the kernel module on every single update. This is automatically handled by APT, but for very small servers it can be slow... at most ~15 mins. Could be solved with private distribution for a large fleet but I can't be bother with that stuff. Hoping at some point Debian will relax their strict "to the letter of the GPL" attitude at some point like they did with install media drivers. But it's not the worst experience, at least installing is automated.

zfsbootmenu https://docs.zfsbootmenu.org/en/v3.0.x/

Also nice way to recover zfs if anything goes wrong. yea, it's a linux image for just booting. But you put it as an EFI image, and works great.

I've been running zfs on root on my Debian home server, only the install was a tiny bit more involved but it was done in maybe half an hour going off of the guide and trying to understand everything it was doing with 0 experience (... And then did it again after I broke networking after an hour lol)