No release notes for the r5 update, if you are upgrading from firmware older than 72.8.0.6 then this firmware will also include the Channel Access feature and Local settings that were enabled with the 8.0.6 firmware.
No release notes yet - new features for IPv6 only.
NB - we have just learned that there will be a further new release next week, so would recommend that you wait for that as the changes in this release are minimal.