Regarding DataTau I built a small front page analyzer and have some graphs up. It runs every 3 hours and looks at some aspects of both HackerNews and DataTau and compares the two. It's still very much a work in progress. At one point I will let it run for an extended period of time.
Graphs: https://github.com/not-much-io/hn-dt-frontpage-comparison/tr...