We will be ending our trip in Zaragoza and it looks like either Barcelona or Madrid are about the same to take a train into. We would plan to stay overnight near either airport. We use miles to book so I don’t think the flights will be an issue.
Any reason we would be better off flying out of one over the other?
There is not a lot of difference. Both are average to small airports. Madrid is easy to reach via taxi from downtown Madrid.
And it's just as easy to get to the airport from Downtown Barcelona. Take the train/metro or the aeropuerto bus.
I don’t consider Madrid’s airport small, but to answer your question, either would work. As the expression goes, “six of one, half dozen of another.”
... classifying airport "sizes" taking only into account how big they are is a useless measurement. What's really important is the amount of passengers an airport has -in relation to its size, of course- because that'll tell you how busy it is.
In this instance, it suffices to say both airports are among the 25 busiest in the world, and the 5th and 6th in Europe, respectively, with 60 and 50 million passengers every year. This means landing/departing in these two airports might not be "a breeze" all the time.
