The json output from 5.0.1 is much closer to 4.2.6, but there are still some missing elements.
Again, we don't use this output in our ebook production tools so it's a low priority.

• The most important potential issue is renditionLayout appearing as reflowable for pre-paginated content.
• Some elements are still coming through as null/false/empty: "navigationOrder" : null, "isHTML5" : false, "referencedItems" : [ ]
• The list of 'embeddedFonts' has moved to 'refFonts'. Not sure if this is a feature or a bug but the fonts in our case are actually embedded.