if the network goes down, it’s ALL going down, so even if the 3rd party name server can tell ISPs where to go to find a site, it’s not going to load anyway…
That’s the view I’m taking as well - in general I try to place DNS in buldings with multiple exits and redundant power, etc, but for hosting if I lose the entire stack of boxes (building in as much HA as I can) then who cares if DNS is reachable when all services are not?
Rsyncing data.cdb is the official way to do things with tinydns master/slave I believe. I have to admit that I enjoy working with bind much more than tinydns.