Are you actually suggesting that using asynchronous commit on non-battery-backed disks is safe, while calling the article's advice "dangerous and wrong"? You do understand that asynchronous commit increases your likelihood of data loss, right?
Async commit has nothing to do with battery backed disks or not. That is Fsync. Async commit will bundle multiple commits and sync them at the same time. Depending on how you configure it, you stand to lose as much as the last X seconds of commits before the server went down, and never more. (you can configure it to lose much less, it's configurable!).
It's all a tradeoff of reliability and recoverability vs performance. Postgres gives you lots of choices so you can make the tradeoff that is appropriate for your data.
