I strongly disagree. If I have an 8 disk server at home with mirroring, the pool could only take a single disk failure. The usable space would be 50% of the total disk. Further, I'd have to buy any extra disks in pairs.
If instead I ran RAID6, I'd have 80% of the disk available and I could add disks in single disk increments.
I think ZFS makes great sense for businesses that can throw money at disks but for smaller businesses or home servers it's kinda bad.
I think it's not a very good idea to design storage solutions around how inexpensive it is to add capacity to them. Your 9+-drive RAID6 is going to take forever to rebuild; 4+ mirrored vdevs (or mirrored RAID of course) will not be a problem at all.
It was kind of a pain to configure (albeit quite flexible) but it's been pretty nice overall, already survived 1 disk failure and a capacity upgrade (during which I had to resilver after every individual disk upgrade, which was time-consuming, but after the last disk got upgraded, the extra space finally showed up)
If instead I ran RAID6, I'd have 80% of the disk available and I could add disks in single disk increments.
I think ZFS makes great sense for businesses that can throw money at disks but for smaller businesses or home servers it's kinda bad.