Reduce HTTP Requests
When AJAX tabs are enabled, and the user clicks the Edit tab, they are then instructed to reload the tab. This results in 2 requests to the server, when only 1 is needed.
Additionally, if an article is in a Book, clicking the Index tab will access the server via AJAX, which will in turn tell Javascript to reload a different page. This also results in 2 requests to the server, when only 1 is needed.
This can be avoided by simply not using AJAX to load the Edit or Index tabs.