I didn't fly there as often as you, but ... I also flew into City Airport a few times in the late 90s, when Pro Air offered cheap flights to there from various cities, including Baltimore (BWI), and I'm not even from Detroit. I mean, it obviously was not seeing passengers anywhere near the scale of Detroit Metro, but…

Finkenwerder (Hamburg) is undoubtedly impressive, but if I'm not mistaken, the only thing they do there with respect to the A380 is cabin furnishing & paint (well, and European/Middle Eastern customer deliveries) ...