First I would like to say that Gonzalo is a very good host!
I stayed at his place for a little bit longer then a month, in the end of my stay the Corona pandemic hit Madrid. I am working in aviation so my schedule was very uncertain, with changes day by day. Gonzalos hospitality and kind way of dealing with changes several times made the end of my stay very stress free! Thanks again Gonzalo!
Regarding the place.
It is modern, clean and has all the features you need. I would recommend this place both for short and longer stays.
Walking distance to terminal 1 (Ryanair) is about 25 minutes, there is a bus going from around 06 to midnight just a few streets from the place.
To get to the city centre is easy. The subway stops a couple of minutes walk away and takes about 30 min to get to nuevos ministerios. If you want to go out late in Madrid there is a night bus back to Barajas, or Uber that cost about 24e from the centre.
All in all a good place to stay, Barajas is full of life as well!
I highly recommend staying at Gonzalos place!