I would recommend you to stay away from the CP and HI at the airport.
Though I have only stayed at the CP, the HI is just next door.

The hotels are not near the airport, and the area in which they are situated is boring at best and terrifying at worst. Basically they are in the middle of no where, next to a highway in an area of demolished houses.

But I do hope you enjoy Madrid, it is a lovely city.

Safe travels.