ZFS: SAS v SATA - does it matter?

If you can avoid SATA disks, please do so. Nearline SAS is a good compromise for people using ZFS who want stability, performance and capacity. You don't need proprietary silent data corruption technologies from the disk manufacturers...

The arguments against SATA really come down to the implementation and choice of storage hardware, controllers, enclosure, etc. It's much easier to go wrong or to find a particularly toxic combination when SATA is in the mix; e.g. behind an expander, using bad controllers and in various failure modes.

See: How can a single disk in a hardware SATA RAID-10 array bring the entire array to a screeching halt?