Sounds like someone finally cottoned onto what Honeywell did on their drive systems under CP-6.
I don’t really like RAID 6 though. For a small installation of five drives, you might as well add one more and get RAID 10. for larger installations the big problems comes in drive rebuild times. With very large drives, the rebuild of one drive of a RAID 5 can take so long the risk of failure during the rebuild becomes more and more significant. RAID 6 just pushes the problem off a bit.