> Europe for an hour and ask them after which differ more, I would bet serious money they will always pick the two European countries.

Only because of superficial things like language. When it comes to politics and the role of government, Europe is pretty consistent. Barring language and architecture, this makes cities all effectively the same pattern (high density, trains, buses, expensive per sq foot).

The gulf between life in the sprawl of Dallas and the density of NYC is far greater than the difference between Paris and Rome.