The outstanding known bugs in the btrfs parity raid levels of 5/6 has come up again on the linux-btrfs mailing list recently:
Linking for context: https://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg79535.html
but note that our current kernel version is falling behind some of these fixes.
So in that context it’s really just btrfs raid1 and as @Haioken states btrfs raid10. Though I’d favour raid1 for it’s greater simplicity.