I use Vellum. It converts to PDF and EPUB, which is all you need for self-publishing books (I don't know about other destinations). I'd never heard of ASCIIDOC.

Finally, one thing that I really, really wanted, and YMMV. There's no reason why you should care about it, but I did: drop caps (the first letter of a section is 3 or 4 lines tall). I just think it's cool. You could do it with a lot of machinations in Scrivener, but it's trivial with Vellum.

Vellum knows all the things about publishing conventions. What I prefer about it is, you pay money for it. That gives them a stable business model.