As an editor at Electric Spec, I've worked with authors from around the world and in a huge variety of subgenres and voices. You know who my favs are? The professionals. How do I define a professional? Not the same way SFFWA does. No, I don't care how many sales an author had or to whom. Instead, I consider a professional author one who can understand and accept editorial changes and feedback, one who understands working with a deadline and therefore responds quickly, and, most of all, one who is kind and courteous in his or her interactions with the editor.
We've been lucky at Electric Spec. The vast majority of our authors are pros. The rest? Well, they have an important lesson to learn before they are truly successful.