I can't imagine not using an outline.
I've always been a very natural writer, never once used an outline, even when I was required to do an outline I would never use it while actually writing the paper. I think following the strict structure of an outline would inhibit my writing style actually.
I agree, usually.
Interesting. I find an outline extremely useful for organizing my thoughts and building an argument. I've never found them restricting because as I write sections are moved around, dropped, merged, or new ones added. The outline isn't in stone or anything, but without it most of my papers would be a bit of a mess.