An RSS feed can help your hub with google ranking for sure. It acts as if new information is being added to your work (in a way), which google likes: something akin to updating a hub regularly. Use this tool with restraint, as too RSS feed capsules in a hub can have negative results. This type of tool adds credibility to your work, but can also detract from credibilty. So, whatever "link" "tag" or "RSS" feed you choose, make sure it is derived from strong quality content, as your choices will be reflected in your ranking with the big search engines. RSS feeds also give your reader more options for gathering information, which in turn, also increases your reputation as a credible writer.
Hope this helps~