As with any new technology, if you like ROR, use it. If you publish a ROR, it's an endorsement - with usage, ROR will increase in popularity, and maybe the format will become more common than it is now.

ROR and sitemap are not the same thing. If you're using ROR just to list the URLs on your site, it's redundant. A sitemap.xml does that.

A free ROR generator is not hard to find. Try a search engine.