I used to use Final Draft, then I started reading more into the fountain format and that got me interested in giving it a shot. I’m not sure about the other platforms, but Slugline is pretty amazing. I still do most stuff manually. I make my notes, beat cards, outlines…everything I do manually. With the outlining and comment system, I am able to put a lot of that directly onto the page. This allows me to mark out my structure, comment, omit parts of text (instead of saving, starting a new draft), and a ton of other useful, but inobtrusive, functions. The open source application, is, in my opinion, the future of screenwriting. I believe this is the best platform to learn fountain, and put it to use. Includes all the modern features you would want like Courier Prime options, PDF exports, modern approaches to writing direction are extremely simple, wonderfully done imports. I copied text directly from Final Draft, dropped it into Slugline, and had 40 pages formatted perfectly in about 15 minutes—after I had gotten the hang of the fountain language.
In short, couldn’t recommend this product more and I have zero doubt fountain, and Slugline, will change some of the ways that even Final Draft approaches the UI. It’s quickly becoming a virtual spiral, for me, in it’s malleability. Buy this! Final Draft is a waste of cash, especially for you younger screenwriters!