I've lived there, a few times, as did my older brother. The cities always felt awful, barring Seattle, bits of San Francisco and bits of Boston, and the bush usually felt okay. But to me, America always had this sensation of something boiling underneath, ready to burst out and tear things apart. Not just the human part of the cities either - I always had this sense that the land underneath was about to pick itself up, have a good shake and knock off all the stuff that was crawling on it.
Los Angeles and bits of Chicago just made my skin creep, as did New York. I think I'd settle for our wild extreme weather and venomous wildlife any day. Europe seems more welcoming to people, Australia is too old and tired to really care, for the most part, though parts of the land here are really hostile and will kill you if they can, and other parts are oddly welcoming - often areas quite close together, strangely. But I doubt I could live in America again, except maybe the Pacific North-West, or around Big Sur, or just about anywhere in the desert.