I've only ever glanced through Superman comics so I'm going out on a limb here:
Surely the more realistic and believable the citizens of Metropolis are as characters, the more heroic Superman's deeds wil appear. This works the other way too - if some villain moves against Metropolis his acts will seem all the more terrible.
The people that Superman is fighting to protect should be given some degree of individuality rather than being portrayed as some faceless abstract, otherwise how is the reader supposed to care about them and how are they supposed to care when Superman saves them?
So in answer to your question - yes.
If I had my way I'd run a Metropolis Central style title in paralell with one of the Superman titles, with minor characters being fleshed out in 'MC' and then making occasional low key cameos in the Superman book.