* Some stuff got published that was important and vital (though its impact on public policy was ultimately minimal).
* Some stuff got published that simply shouldn't have been leaked --- for instance, details of technical implants useful only in narrowly targeted espionage.
* Some stuff didn't get published that should have been --- for instance, in light of what we later discovered about Juniper/Netscreen, had everyone to do this earlier, a list of vendors impacted by VPN implants would have been helpful, and could have been doable.
* Some stuff got published that were simple false, such as the notion of a "PRISM" system that gave NSA direct access to Google's systems.
A more carefully curated, competently explained process of leaking could have improved all these outcomes, and that's exactly what Gladwell is suggesting Ellsberg accomplished that Snowden didn't.