There are many different styles of writing. Almost as many as there are types of documents and stories out there (maybe even more). That said, the most important rule is to write. Get it in the page. The problem with editing as you write the first draft is that you are writing from the critical part of your brain and not the creative part. Not only does this slow you down, but often it prevents you from completing your task, and thus, you never finish your story. the demented elves ask that no matter what you are writing, please finish what you start. You may have the next greatest story ever told, but if you do not finish, no one will enjoy your story.