A lot of the time spent in the revision process involves getting to know your characters and story on deeper levels. I've noticed that it takes me a whole draft to get the story, then maybe two or three sets of revisions before I really know the characters. It's good to know I'm not the only one. In responding to my post on when to stop revising, here's what some of my commenters said:
Tabitha Bird: "I know to stop writing when I can write a good query letter. When I can sum up the book and I know what it is about and the whole thing makes sense, then I know I am there."
Karen Strong: "I can't even began to tweak my pitch or query until I'm almost near finishing revisions. I just don't really know yet until it's at that point."
I suppose that's why some people make character sheets, setting descriptions, highly detailed plot summaries etc, before they begin writing. But until I put my characters into situations where they have to act and react, I don't really know them, or the surprises they will bring to the story.