Thanks for sharing such a nice information with the community.
Let’s conclude: The rule of thumb “do a save every 1000 nodes” might be a bit too optimistic on AEM 6.2 and older (with default values), but ok on AEM 6.3. But always keep the amount of transient space in mind. It can overflow your heap and to debug out-of-memory situations is not nice.
Sums up very nicely.
~kautuk