Question about RAID5/6 stability

Can someone provide an update on the status here?

The BTRFS wiki hasnt been updated since Feb and it refers to v3.8. I notice the latest rockstor is running v4.
Has the write hole issues been resolved?

I think my post here is along these lines, it could be combined and possibly moved to features.
http://forum.rockstor.com/t/btrfs-raid-parity-beyond-raid5-6/154/1