PHP - Reasons to use Iterators?

I was perusing the manual today and noticed the various iterators. To me, it seems like they are all somewhat pointless; I don't see a reason to use them unless you prefer their syntax, or don't know how to write a recursive function. Are there any reasons to use built-in iterators in PHP over just writing a loop or making a recursive method?

I'm only looking for factual responses, not subjective preferences (ie: I don't care if you think it's more "readable" or "more object-oriented", I want to know if they're faster, offer functionality that can't be achieved when rolling your own, etc.).