I can´t tell what you need, since I don´t know your needs. But I can tell you how I use the program and why I think it´s valuable.
To summon I use OO for reference notes and as a part in my workflow for develop ideas to solid projects.
I use OO in many ways. Foremost I have a workflow where I mindmap, export to .opml, open in OO and work more with the text, maybe go back and forth between mindnode and OO to develop my idea, finally I export the text again and open it in Scrivener where I write my final draft.
I have about the same workflow when I brainstorm and develop project ideas and projects, except that I don´t do the final draft in Scrivener, instead I drag the oo-file over to OF and make a projekt of it there.
I also use OO for notes, and since I can view OO-doucments in Devon Think, I use it for reference notes of different kinds to projects in OF.