While I am one of those that would hand over my saved stories, I wonder about the validity of any conclusions you would draw from the group analysis due to the dual nature of the save button. The same button that is used to up vote an article is also the same button that HNers use to save an article to read later, but might not upvote the article after having read it. I'm not quite sure what could be concluded from such an unclean data point.