AS3 Worker - External or internal SWF?

I’m playing around with threads in AS3 using the Worker-class.
I’ve searched for tutorials all over the net but haven’t managed to find many enough to get some questions solved, so I’ll ask it here!

The thing with the Worker-class is that you can run another SWF side by side with your main SWF and share memory though there.

Some codes I’ve seen is creating a whole new SWF and then just embeds it into their code using the [Embed].
Others are doing it internally within one SWF like this:


So my question is!
Which of these way are the best, or is there even a difference?

Thanks in advance,