I tend to edit as I go, too ... not something I'd suggest for those authors who have trouble finishing their first drafts. I haven't had to make really major changes to this story--just added to what was already there. But I've had to do major revisions before, and I really, really hated it. I won NaNoWriMo once, and realized that fast writing style isn't my thing.

In any case, editing after a draft gets cold Is a must.