Editing books, meaning acquisition editing as opposed to copy editing, is way different than writing them. It's really a different mindset. With Dry Gulch, I'm trying to decide what I want in the way of stories. Will I get more or is this what I have to choose from? Which stories fit better? And then, it starts coming together and Dry Gulch goes from abstract concept to real life anthology.
The down side on something like Dry Gulch is writers won't write to guidelines--they try to convince themselves their story fits a certain project. If you have an open ended project like a horror anthology and you just say "Send me horror" there's a lot of that lying around and you tend to get a lot of stories. My stuff is always highly specialized and I don't get that kind of deluge, accordingly. Still, I'm mostly pleased with what I've gotten.