My advice to anyone new: Don't worry about the expansion zones. Don't give them any more thought than you would of any other zone X levels down the line. Ultimately it's just more of the same game you're already enjoying, and it's silly to race past one perfectly enjoyable part of it just to reach another equally enjoyable part. Rushing to the end is like scarfing down a really good meal and then being sad when there's nothing left but crumbs on your plate.