Russ, do you mean to say that when exporting, the files are rendered automatically?
Not saying the project gets rendered, but the exported file does. And its appeal is that it's a very fast process.
For example, I just had a 5 minute project (h.264 clips) with effects/title, and, as you would expect, the orange render bar ran the length of the timeline. Background rendering was off. I exported the unrendered project as an h.264 Quick Time and it completed the task in just about real time. (BTW, this is something I never would have attempted in earlier versions of FCP.)
So I ended up with a self-contained QT movie file. If I had intended to make several delivery versions (for disk, Web, ATV, etc., I would have exported as Pro Res and brought that into Compressor.
While the project remains unrendered, it doesn't matter to me. If something comes up that requires me to make changes and create a new version, I can easily do that because of the speed with which it exports. (And I have used up far less storage with this workflow than if had created a whole lot of render files.)
Again, the only time I do any rendering is if playback starts to interfere with edits. And that seldom occurs in my projects. (You might find this iinteresting; note all the unrendered sections of his timeline while he continues to edit on the fly.)