I have tried Scrivener, which is quite complicated. Then moved to Ulysses III. I just love the way it handles texts. Beautiful and simple app, very flat learning curve. Highly recommended. I pair it with Daedalus, the same company's iOS app, for note taking and jotting on-the-go, and it automatically sends notes to Ulysses III.
If you are looking for an outliner , then I would recommend Tree app (software maker: Top of the Tree of Japan). Elegant and simple, and again very intuitive.
Mindnode pro is another beautiful app for mind mapping.
Now I outline in Tree and save the file as .txt and then open the file in Ulysses, and start writing. Ulysses can export files in various formats, so does Tree.
Word or Pages can be used for formatting and finishing.
I guess the topic is about hardware and not software. Interesting, though.