Which is why the 3 and 4TB drives I have in my FreeNAS box at home are configured as mirrored pairs, the time it takes to resliver a drive in this configuration

Which is why the 3 and 4TB drives I have in my FreeNAS box at home are configured as mirrored pairs, the time it takes to resliver a drive in this configuration is already fairly long - RAID-Z or the hardware equivalent of RAID-5 would take upwards of days to complete and that's a disaster waiting to happen.