David, it would help if you gave a bit more background to you, your course and your assignment. I hesitated when the link took me via a FacePrune warning.
You questions do not enable me to say why I choose to fly from various airports on different occasions. Each flight has these factors: cost (incl vs train) overall time travel, availability of flight, availability of connections to final destination, use of single airline from start to finish (so airline will look after me if the feeder flight misses my connection). For me facilities at the airport are irrelevant - as long as I know what they are I can compensate.
In my business days other factors influenced - one preferred airline for frequent flyer points, time of departure to enable me to maximise my working day.