I'm not sure. I've got a Mexican friend at Creative Writing and I can definitely hear similarities in his writing voice and that of the writers in this collection although, on the whole, he's a much more accomplished story teller than most of these authors. Of the 12 stories, I think I only really liked 3 or 4. The others were either just too short, or confused or just not particularly well written (or perhaps translated). There is an excellent introduction, entitled Snow White vs. Dr. Frankenstein, which does a lot to explain Mexico City to the outside although it does little to convice that it's the "best city in the World".
"Outside the door" in which neighbours discuss what to do about screams coming from an appartment in their block is possibly the best story and there's one about an assassin which is the only true archetypal noir story here.
I've moved on to Voices from Punktown by Jeffrey Thomas, another anthology set in his post-cyberpunk hell hole colony world. It's a mixed collection and, to certain extent, the city is more the star than any particular story. But it's right up my street so I'm getting much more from it than MCN.