Stone - you won't get a definitive pre-soak answer. It's one of those things. What Ilford is saying is it is not required. That doesn't mean it is bad, just not required. PE prefers a pre-soak in all cases (excluding divided development of course) because it can't hurt, and could potentially help prevent certain potential unevenness issues when pouring developer onto dry film in a tank. It could help when either development times are short and/or when using a more active developer, or when filling a large tank. He explained it more thoroughly in other threads. Some people also like a pre-soak as a way of bringing the tank/film to development temperature, if the ambient temperature is significantly different than the planned processing temperature.