It was not that reliable for us. We still had unexplained occurrences of IP caching and it's easy to fat finger the configuration and lose the resolving functionality. Anyway, as I mentioned haproxy has vastly superior load balancing capabilities. Nginx still has a lot of work to do to match haproxy in this area.
Also, the author doesn't mention it, but you can also set a custom cache timeout with the valid=Xs option.
http://nginx.org/en/docs/http/ngx_http_core_module.html#reso...