Most of the characters are flawed, that's what makes them seem real. The more you watch the more you get to like them (well, some of them). Even the 'bad guys' have likeable traits, they aren't black and white, the characterisation of both police and gangsters has real shades of grey. IMO that makes it even more brilliant, not less so. Things with formulaic characters that are obvious are predictable and tedious after a while. Omar, the gay gangster who robs drug dealers is a perfect example. A fantastic character. And the different series do focus on different things- the Port Authority, the press, the city hall and politicians, but underlying it all is the war on the drug dealers. Quite simply brilliant.