Every author must decide what is important to him or her in an editor, but in these days of electronic communication, honestly I do not think it is important to seek a local editor unless your book is specifically related to something of local interest. Even in that case, you may benefit from the perspective of someone who does not have all the local knowledge it can be easy to presume, so that you can prepare your book for a wider audience.

Attention to detail is a critical skill for editors. So how do you screen out editors who might not wield a virtual red pen with the chops to catch every typo, grammar problem, style issue, and the like? You could post a job ad for an editor and subtly screen out applicants that aren’t as detail-oriented by including some fine print in the description.
If “the greatest benefit of an editor is that he is she is not the author—the editor is someone else,” then an editor is no more than a beta reader, and all authors would need is friends to read their novel and give feedback. I recommend beta reads before a book is sent to me for editing, because casual readers, approaching the story fresh, can indeed find flaws in the book the author is too close to the story to see. But it’s after the beta reads that a professional editor steps in to do her magic. A skilled fiction… Read more »
Obviously there is a big difference. I actually started with screenplays (with some mild success) partly due to hearing that as long as you have a good story, the grammatical errors won’t be a big deal. Well, that was not true. Maybe if a producer liked the story or I was already established but every contest I entered always came back with feedback about the grammatical errors. Even if I won or placed as a finalist, I always received critique on that. Very little is spelling error, it was more about structure, etc.