I hosted my coding environment on a VPS running FreeBSD and happen to jump between VPS provider quite a bit due to location and pricing. My migration method was simply:

    $ zfs snapshot zroot/home@migrate
    $ zfs send -R zroot/home@migrate | ssh newhost zfs recv zroot/home

ZFS automatic snapshots (via zfstools[1]) can also saved hours of headaches trying to recover an older version of a file. Since snapshot appears as a regular mount (ZFS even automatically expose them under /path/to/mount/.zfs/snapshot), all existing tooling just works (cp, cat, running diff against snapshot, etc.).

My Linux machine these days also runs ZFS, but the level of integration with the system is still far from that of FreeBSD's. That can range from something as simple as ZFS ARC stats in top, to native support for ZFS Boot Environment allowing the system to boot directly from snapshots or do an offline upgrade of a clone of a live system[2]. (On Linux side of things there's zfsbootmenu[3] which provides something similar but the project is still quite new.)

The filesystem may not matter that much, and I'm sure many these features can be replicated with LVM, but having a unified tooling and community around it really makes quite a difference in quality of life as an end-user.

[1]: https://github.com/bdrewery/zfstools

[2]: https://vermaden.wordpress.com/2021/02/23/upgrade-freebsd-wi...

[3]: https://zfsbootmenu.org/

I can't speak for your computing experience, but for mine:

There are significant differences in performance, admittedly SSDs temper these differences but there are plenty of systems with large HDDs. This isn't an abstract performance benchmark thing, I feel it when doing operations on large numbers of small files.

There are significant differences in features that impact how you use the system. For instance, sometimes I like to backup a directory I'm working in (typically before some funky git operation), normally that can be done with cp or tar, but that's slow. Much faster is a manual filesystem(/volume manager) snapshot. But I have to remember to do that. Much more convenient would be if I didn't have to explicitly create a snapshot, which HAMMER would offer me.

All non-temporary HAMMER filesystems in DragonFly by default automatically maintain 60 days worth of 1-day snapshots and 1-day worth of fine-grained (30-second) snapshots. - https://www.dragonflybsd.org/features/#index3h2

It sure does. Compression and encryption and snapshotting and bit rot protection all native to the file system and the tools around it instead of having to cobble together lvm and mdraid and such.

Snapshotting imo is one of the best things. Copy on write file systems really are awesome. And FreeBSD adopting ZFS so early was a huge win imo.

Depends. In a perfect world it doesn't matter. However in this imperfect world it is nice to know that there is an automatic backup of your files from a few days ago, and if a hard drive crashes you just replace it (requires paying for redundant hard drives!). The ability to add more space to an existing filesystem is nice just in case.

There are a lot of other features that might or might not matter to you. If the above don't it is because you haven't been burned yet in life. (Or you use one of several other filesystems that support those features)

Short answer - automatically cache frequently-accessed files on expensive but small NVMe drives while using bigger cheaper slower drives for mass storage.