What is more convenient -to check in a hotel near to airport or in downtown?

I m asking about the capitals and big cities,never mind where they are.What is more convenient -to check in a hotel near to airport or in downtown?
If you are flying in one day and out the day after, obviously the airport is a sensible choice. Probably better rate too. However, most European airports are far, far from the city center and transport to the city and back is very pricy. For example, an airport cab might cost 50 euros one way. You could use public transport, but it could take a long time and wouldn't be too convenient at night. Old Euro cities were built for people living in the city and the central areas are most convenient.What is more convenient -to check in a hotel near to airport or in downtown?
If I'm there for sightseeing or business, I prefer to check into a hotel in the city rather than near the airport. I generally use airport hotels when I have a very early morning flight out. The Bologna Sheraton, for example, is just outside the airport. The shuttle starts at 5:15 am, so it's easily possible to make an early flight and they start serving breakfast before 5 am. However, there are only a couple of shuttles a day that go downtown, so you need a car or a cab most of the day if you want to spend time in the city.





Airport hotels are convenient from the perspective of dropping your bag off quickly, but in the bigger picture, the city hotels are usually more convenient for the actual stay.