I realize this may be a surprise to many, but Luxembourg City is not a major airport hub. Though an advantage of living here is that the city is centrally located within Europe, a downside is that most flights must be routed through larger airports. British Airways flies through London, Lufthansa through Frankfurt, KLM through Amsterdam, and Swiss through Zurich. I would mention that Air France flies directly to Paris, but the train provides convenient transport to the center of the city in just about two hours. Hence, factoring in security, checking baggage, the clusterfuck that is CDG (which is several miles from the city), and the fact that–on an Air France flight–you have a higher chance of ending up as fish food in the Atlantic over what could have been a very fixable error, there is little reason to discuss Air France for European travel.
Anyway, for us, most places in Europe require a stop in one of the above cities, and this was our layover coming back from Spain. It was a nice way to spend a few hours, but I’m not sure I would suggest Zurich as a priority destination for anyone visiting.