Content editing comes at a range of intensities. The intensity of a content edit shouldn't depend on the editor, but on the needs of the author, his book, and its writing history.
I've edited a couple of books that were a long time in the writing. In one case, all told from the creation of the first chapter to the completing of the final chapter, 15 years of on-off writing. These are the ones that require the most work from the editor, because even when the author's concept of the original story hasn't much changed, the author himself will have changed over the time of writing, and the reader just isn't going to take 15 years to read it. The editor has to try to find a way to make it all into a single, cogent work. My advice to the author is to get an editor to read it and give some general advice on how to prepare it for editing. I call this kind of read-through a pre-edit sanity-check. Why a sanity-check? Because you if you go to a full literary edit too soon, it will cost you a fortune.
I have a couple of authors who produce short fiction that sells reasonably well. When the author has enough experience a given style/genre, and when he has enough experience of producing coherent stories, very little beyond a copy edit may be needed. At this point, he might still want a sanity-check. Why a sanity-check? Because you might still have a story-breaking plot-hole, or one or two minor issues that a second pair of professional eyes will see.
This post is called 'sanity', not 'sanity-check', for a reason, though.
Whereas a good copy editor can take your manuscript and send it back to you near as dammit CMS compliant, beyond copy editing, it can be very hard to judge when editing is finished.
When a writer sends me an extract for a sample edit, I generally edit quite intensively regardless (or indeed ignorant) of the overall quality of the manuscript. I want the writer to have a strong idea of the kind of editing that I will do. But my approach may be different once I have the whole manuscript in front of me; and may evolve further once I have discussed in depth with the writer.
I like to think that after working with me, a writer will have a better sense of his own style and own writing process, and that he will also have a story that is more coherent, clearer, tidier, but which remains resolutely his own story. I always repeat that my aim is to help you make your book as good as you can make it. Along the way we will of course deal with linguistic necessity; I aim to sensitize a writer to his writing habits and techniques, by drawing his attention to what, for want of a better word, we normally call errors.
So far so typical. But there is a reason why I am always going on about how important it is to find the right editor for you: editors don't all work the same way. We don't all have the same education, the same reading and editing history, not even the same ideology - even though most of us refer to the same selection of texts when arbitration is need.
When I read non-fiction, I can positively identify when a professional edit has been done. This is much harder with fiction, because while content editing for non-fiction is all about structure and clarity, content editing for fiction is much more creative. In non-fiction the editor can also make much bigger changes, because changes are justified on the grounds of communication, not of art. Fiction is much more personal. Most of the authors I know are happy with my saying: "this paragraph needs work," happier still if I say "this paragraph needs to be reworked so that the attitude of the character is clearer", but very unhappy if I rework the paragraph for them. How far I chuse to go is much a matter of my feeling for what the author will accept.
Other editors may choose (other editors generally choose, and I only chuse when I'm blogging) to go further or not so far.
So suppose you get your manuscript back from your literary editor; you rework it in accordance with the editor's recommendations, but you still aren't happy with it. This might mean your editor wasn't a good match for you - though there may be all sorts of other reasons. In any case, should you get a sample from another editor? Go for another full content edit by someone else? A literary editor is more like a collaborator than a quality control technician. With each editor you will get a different book. So if you've already tried more than one editor and you still aren't happy with the results, how do you decide when to stop? Go to another editor? In my opinion, that way, madness lies.
Go to another writer, or go to an editor, and ask for a sanity-check. In this case, tell them the whole history of the manuscript before they read it. Make sure they know which version they are reading! Ask them to help you to decide whether you should invest any more time and money in it; whether you should get it copy-edited and publish it, or whether you should go for another full edit.
There are two questions an author should ask himself before hitting the publish button. Number one is: "should I pay for a professional copy-edit?". The answer to this is always yes. Number two is: "should I pay for a professional literary edit?". The answer might well be no.