Well, technically, if you are going back and forth between your outline and your first draft, then you haven't outlined it properly, or you have started writing too soon. You need to re-think the purpose and content of your outline.

GoogleDocs was my second-best writing environment, and I loved it when I worked at a tech-savvy company that had standardized on the full GoogleApps suite. But Google's apps fall down as soon as you need to use them with ANYTHING else.

Markdown has also been on my radar, do you use that as syntax for iaWriter?

I find any sort of markdown notation a distraction. It is, once again, confusing CONTENT with LAYOUT. Stick with writing excellent content, and then worry about the layout later. That way you will ensure that your content is good, before you dive into the distraction and bottomless pit of layout.

... which brings me to ...

InDesign.

It really is amazing. Brilliant app. But it is a bottomless black hole pit of despair unless you get professional training on it. I use it pretty much weekly, and I massively destroy things with ID pretty much weekly.

At this point, if I can get a page to look right in ID, then I output it to PDF.

Then I assemble the individual PDF pages in Apple's "Preview" app, into a full, multi-page PDF, and print it out.

Sometimes I hand-type page numbers into Preview, as well. (shrug)

Writing is religion. I know kb is going to have a lot to say on the topic too, and I look forward to reading his excoriation of my technique! :-)