My comment was more about the reliability of replication across geographies (author writes, "and it will be stored redundantly in news servers all over the world.")
The par2 files would be more surefire if you're using your own subscribed newsserver in a closed-loop fashion for backups. However par2 technology doesn't mean NNTP will guarantee those parity files actually got replicated to other servers.[1] If one is looking for safety beyond your own newsserver, you'd have to consider increased probabilities of failures. I think that's ok for sharing rips of Blu-Ray movies. However, for the irreplaceable backup photos of your children, hoping for par2 files on other Usenet servers you don't subscribe to may be too risky.
The par2 files would be more surefire if you're using your own subscribed newsserver in a closed-loop fashion for backups. However par2 technology doesn't mean NNTP will guarantee those parity files actually got replicated to other servers.[1] If one is looking for safety beyond your own newsserver, you'd have to consider increased probabilities of failures. I think that's ok for sharing rips of Blu-Ray movies. However, for the irreplaceable backup photos of your children, hoping for par2 files on other Usenet servers you don't subscribe to may be too risky.
[1] http://ask.metafilter.com/237447/How-do-files-on-Usenet-deca...