The question isn't whether Obscurity provides security at all, but rather if the tradeoff you make with ease of use and maintenance is worth it.

From my experience obscurity is usually trivial for a determined attacker to overcome, and if it's not a determined attacker your normal security layer will probably be insurmountable to an attacker of opportunity.

For the small time (let's say an hour) that it'll add to a determined attacker's time you force your users to use an extra key just to detect the ssh port your using (the example he used in the article).