Where does everyone stand on the great plotter versus pantster debate? The question reminds me of a tee-shirt popular in the early days of computing that read: There are 10 kinds of people in this world -- those who read binary and those who don't.
Those of us who tend to be more linear, left-brain types like to plan out our plots. Planning may be a habitual approach to life, but I call a big white piece of paper with a visual storyline a sanity-saving device. No longer having to worry about plot, the writer is free to focus on character and scene.
For the truly artsy, a plot planner is confining rather than liberating. Many writers have said that they only found the right voice after they stoppd planning and just let the ideas run.
I've found that my cortical preference has a bit of both hemispheres. I want an outline, the more visual the better. But I don't want it too detailed. I want to be free to improvise when I suddenly discover that nothing in the story's middle is ever as easy as it seemed when I started.