Earlier quoted context omitted.
False. If you use a language that's homoiconic (any Lisp), you don't need to serialize anything. The source code of the language is already in its serialzed form. You can't beat the speed of not having to do something in the first place. As an aside, no sane person would write a SOAP webservice today.
I wrote a SOAP webservice -- not because I'm insane, but because our business relies on data sent to us. We could certainly tell everyone that they'll need to write code to send us the data we need to be of use to them. Or we could look at the installed systems that hold their data, and see what built-in support those systems have for external integrations. And so: we quickly added a simple SOAP endpoint. About seria…
If the language you're using is already expressed in a form that does not need serialization, then you don't have to serialize it. This is the very essence of languages that are homoiconic. Perhaps you should familiarize yourself with that before down-voting what I have to say about it.