Depends on the source of the whey, in how processed it is. It may come from milk, but does not have lactose, or the same chemical build up as mild does. As whey is only one constituant.
You can get whey from pure organic un pasturized milk.
It is better then soy protein. (unless of course you are having soy from organic, fermented soy)
It also depends on what each body needs to feel healthy. Don't you agree?