Ask HN: Who is using microdata (HTML/JSON-LD) on their pages, to what effect?

On some of my pages I had marked up some rReview areas long ago, and Google does indeed often display those snippets well in organic search results. But over the last couple of days ... ahem as a displacement activity ... I added lots of markup to make 100+ of my pages into schema.org/Article, add Organization info to the footer, and in particular marked up one trial DataSet with JSON-LD. Has anyone noticed any (systematic) effects good or bad with such markup? In particular, how to use the DataSet stuff well* does not seem clear to me. *Eg would 'well' enable the Skynet automatic semantic Web just after both people switch to Linux on the desktop? What would 'well' mean?