Simply amazing filesystem. This is years ahead of most other filesystems. The IT community has been waiting for someone to redesign the filesystem instead of changing or upgrading year after year. ZFS is self-redundant, meaning no expensive RAID controllers or rebuilds. Compression is built in, and you can even use deduplication.
Room for Improvement:
Drive scrubbing needs to be run every week for consumer drives, and every month for enterprise drives.
This truly an up-to-date filesystem with advanced features. Deduplication is a must in many enterprise environments. It is very flexible and surprisingly fast. While ZFS uses more ram than other filesystems, there is not a need to upgrade servers. It scales according to your system.