Working with a professional editor can be one of the most rewarding experiences in an author’s life. You’ll probably learn more about the craft of writing — plot, characterization, dialogue, worldbuilding… — than if you took an creative writing course.
However, as is always the case in creative endeavors, critique can be hard to accept. This is why you should seek an editor who’s not only experienced in their field, but who you’d feel comfortable receiving feedback from.