Honestly unless you’re just playing with ZFS as an enthusiast looking for something to do, I wouldn’t recommend using ZFS. Someone recently asked about recordsize optimization, which the response gets into the overhead and cost benefits of raid6 vs raidz2. In a nutshell you’ll lose about 20% of your capacity, after removing parity disks, of actual usable space.
Is it REALLY worth it to you for 20-30ms~ response time difference?