I'm more interested in the patriotism of this place. It feels very distinctly American. The architecture is pretty much a copycat of Southern mansions, you can hear a guy listening to, oh, I forget the name of the tune, but it's essentially American patriot music. It's stated that the game has a Wild West feel to it as well. The setting takes itself from 1870s America, surely, but the characters take themselves from the hardboiled genre. The main character, for the most part. Disgraced PI? Likely a cop that was fired for insubordination. Disgraced PIs test highly on that. So do hardboiled detectives. Another thing, hardboiled detectives have a tendency to try to fix America all by themselves. Given that this giant sky city is the ultimately corrupt flagship of American patriotism, the theme that he's coming here to purify it will pop up.
That's why I have to disagree with the notion that Columbia is simply Rapture in the sky. Rapture encompassed the elements of the Cold War in its architecture. It had these skyscrapers with neon lights mixed in with tenements and dilapidated structures, whereas Columbia is highlighted by wide mansions and space in general, meant to symbolize the freedom of America. In a way, Rapture was expressing the depth of the Atlantic Ocean through the height of its buildings, where Columbia represents the vastness of the sky through its wide spaces. It's impossible for one to become the other. There's the sweet irony in that Columbia is an open place with a closed society (because most of these people, if not all of them, are Americans), where Rapture was a closed place with an open society (where Ryan went out of his way to grab intelligent foreigners).
I'm sure the settings are very distinct. However, I'm not so sure if I'll be interested in the game that much, if only it seems you can't do as much with it. I mean, Bioshock was great because you were trapped in this place and it seemed as if you'd entered a House of Horrors against your will. That you're intentionally flying into this city and intentionally fighting this city that everyone knows exists, well, it's just not as sexy.