It's been a few months and a few games now, and I'm hooked. I upgraded to the full version and downloaded the updates and I've been busy pecking away at the next five to ten games in my campaign.
First of all, Scrivener is packed with features. More than you will ever likely use... unless you plan to publish your material, I suppose! That is what Scrivener is designed for, after all.I won't catalog all the features Scrivener carries but I will say it goes far above and beyond whatever your gaming needs may be.
It is an EXCELLENT tool for the GM or worldbuilder. It's incredibly convenient to able to spontaneously organize data for a game or campaign, and even if you only use the linking features it's well worth the $40 to put everything together.
There is a huge Scrivener community, including a number of ebooks, online classes and regular print material supporting the product. Finding an answer to your questions about Scrivener should never be more than a quick Google search away.
Scrivener in your game.
The combination of Obsidian Portal and Scrivener seems like the be-all, end-all of DMing utilities. Scrivener allows you to organize your material and work at it piecemeal in much the same way as a wiki, except that you can actually move the material around without requiring you to re-invent your hyperlinks along the way.
One way that I use the linking is as a local rules wiki. When I create monsters, usually cut and paste from a local or internet copy of the Pathfinder SRD, I can actually use or insert hyperlinks to get to a file or website, which saves me a fair amount of time if I need to look up one of thirty or so special abilities that might be on the table at one time. The only real weakness of the linking feature is that it doesn't seem to support hash-tagging, so if I want to link directly to a feat, it instead takes me to the Feats.html document, from which I have to search to find the pertinent entry. Other than that, it's a win!