I chose this accommodation because my plane to Madrid arrived at around midnight and my return flight was also very early (7am) so this accommodation was perfect for me.
From the airport you just take Metro line 8 to Barajas and walk around 10 minutes from the station.
Note though that getting back to the airport at night might be problematic as there are not so many night buses.
The accmmodation itself was basic and totally OK for the price. You basically have all the basic stuff you need.
The only problem was the lack of a desk in the room. I had to take online classes with my laptop and I had to put my laptop on the commode. I think there should be a desk in every accommodation, especially nowadays when so many people work and study online.
Generally I'm satisfied and will definitely come back!