Scrivener's great right up until the moment when you need to collaborate with someone else, at which point it falls over completely. The usual practice in these scenarios is to write in Scrivener and then when finished export the document to Word format to send to these other parties, but then if they come back to you with edits/feedback/etc. you're stuck with the problem of getting those changes merged back into your original Scrivener document, which is no fun -- especially if you've got multiple rounds of revisions among multiple collaborators to deal with.

Don't get me wrong, I like Scrivener a lot, but in lots of scenarios it just doesn't work as a drop-in replacement for a more general word processor.

I. Love. Scrivener. My workflow is to sketch out ideas in MindNode, drag the outlines into Scrivener, and work in their to flesh them out. I find this infinitely easier and more flexible than outlining and editing in a word processor.

I've heard good things about Ulysses, too, but haven't tried it. I think that whole class of application is inherently better for editing large documents.

Ulysses was fantastic when I last used it to do a multi-chapter document. I separated the chapters into their own files, it remembered each chapter's scroll position so it was easy to look things up in each, and the default templates looked superb.

I stopped using it when it went to a subscription, though. I can't accuse a company that lets you write in Markdown, basically plain text, as rent-seeking, but I dislike my workflow being held hostage like that. Haven't really found a suitable, multi-document replacement yet.

I'd definitely heard good things, but the subscription was a dealbreaker for me, too.

Scrivener has much the same document model, but it's pay-once. That by itself made it much more attractive to me.

There are actually a number of options - given tools like pandoc and org-mode conversion inside of Emacs, there are lots of choices of sane working environments even if you ultimately have to have a Word doc at the end.