My thinkpad from college uses ZFS as its rootfs. The benefits are:

  * If the hard drive / SSD corrupted blocks, the corruption would be identified.
  * Ditto blocks allow for self healing. Usually, this only applies to metadata, but if you set copies=2, you can get this on data too. It is a poor man’s RAID.
  * ARC made the desktop environment very responsive since unlike the LRU cache, ARC resists cold cache effects from transient IO workloads.
  * Transparent compression allowed me to store more on the laptop than otherwise possible.
  * Snapshots and rollback allowed me to do risky experiments and undo them as if nothing happened.
  * Backups were easy via send/receive of snapshots.
  * If the battery dies while you are doing things, you can boot without any damage to the filesystem.

That said, I use a MacBook these days when I need to go outside. While I miss ZFS on it, I have not felt motivated to try to get a ZFS rootfs on it since the last I checked, Apple hardcoded the assumption that the rootfs is one of its own filesystems into the XNU kernel and other parts of the system.