While I can't speak for the NWDA crew, who might give you different answers depending on the specific pre-set, what I can say from my experience of working with the Cumulus pack is that the settings are probably optimised for a broad range of uses (but even then, there will be exceptions), while the seed will entirely depend on the kind of scene you are working with - I know that in a scene I'm currently working on, I changed the seed about half a dozen times (but not randomly) to get the effect I was after. And Seth says in one thread that he often changes the seed up to fifty or sixty times (correct me if I'm wrong).
