Oh, agreed, the original example Joe has is just a language demo. But the ability to change one set of receives for another (that is, "this process listens for messages of type A, and in this one case, changes to start listening for messages of type B", which both Erlang and Scala can do just fine (again, my point was just that something you can do out of the box in Erlang, required a special keyword in Scala, which led to someone familiar with Scala to think you could not do it in Erlang) can be useful. I posted on someone else's comment in this thread with a real world example I had, where I had to change what my actor was listening for.