It makes sense only in RAID configurations, otherwise it’s slower than ext4 in 6 times (the simple single disk zfs and the same disk ext4).
Unfortunately in my tests with default options for raidz and LVM parity volumes I received not good results. On the same hardware and disks the raidz (3 disks) is slower than LVM parity (the same 3 disks and 3 columns) in 5 (!) times for the rsync and a continuous 1G and 2G files 
I tested it 3 times cleaning env before the next test, the difference in results is less than 1%