But what if so many cities have blanket "coverage", that you can't really differentiate. I mean, what if there is not enough separation between cities by that m

But what if so many cities have blanket "coverage", that you can't really differentiate. I mean, what if there is not enough separation between cities by that metric to make a meaningful list? I'd bet that not only the large cities, but the small cities as well would have almost blanket coverage. Small places like Key West, DC, Miami Beach, etc would all tie with the big cities for 1st. Just because the percentage of city blocks covered is so high in lots of places like that.