Hi, professional screenwriter here (USA), and longtime Scrivener user.
The short answer: Scrivener’s organizational tools are so good that I use it AND Final Draft at the same time to develop screenplays. I write pages in Final Draft, then copy them onto the clipboard and use Scrivener’s Paste Text to Screenplay to transfer the pages with formating intact. I do the reverse when I want to do a lot of rewriting. Send it to Final Draft, then put it back into Scrivener. When I finally finish the draft in Scrivener, I export (not compile) an FDX file of the script, and open it in Final Draft to correct formatting and output to PDF.
If you don’t have Final Draft, the completely free and unlimited app WriterSolo works great for this purpose.
The longer answer: I’m really grateful that Keith made an effort to embrace screenwriting features in Scrivener. Unfortunately, he didn’t make the screenwriting features up to the same standards as the rest of the app. I put that down to Keith not wanting to write screenplays, so he’s not eating his own cooking.
From a pro screenwriter point of view, there are two main problems with Scrivener:
(1) it can’t give you an exact preview of your pages, just an approximation. Screenwriters live and die by page breaks. The difference between a two page scene and a two-and-a-quarter page scene can be a big deal. We need to know where we are in the draft.
(2) the word processor doesn’t understand anything about screenplays – it’s built from Apple’s text engine, so it’s like writing in Text Edit with some built-in formatting rulers. For example, Scrivener is the only screenplay app I’m aware of that will paste dialogue into a scene header. (By mistake.) All the others will recognize that the clipboard doesn’t contain scene header information, and will instead insert a blank line, a character name (from source) and paste the dialogue with proper formatting.
Because of this, I only use Scrivener’s word processor for minor changes like fixing typos. If I want to rewrite a scene, I paste it into Final Draft and do the work there.
FWIW, if L&L licensed the script processing code from WriterSolo and made a new app that was Scrivener with a professional screenwriting engine, I’d happily buy a brand new seat. Like I said, the rest of Scrivener is so powerful and helpful, I’m willing to put up with some inconvenience to keep it in my workflow.
Let me know if you have other questions.