The apartment despite being small is extremely spacious and has everything you will never need for a stay in Madrid. It's extremely well connected just 100m from a metro station with 3 lines that bring you everywhere in a matter of minutes. The photos are almost misleading as in practice the apartment is much much nicer and the terrace at the entrance is an amazing place to take breakfasts and so. It also have air-conditioning everywhere but we never needed it, even though we had 37° C for 2 days if we kept the windows open there was enough passage of air to make AC unnecessary.
Small note, Maria prefers to speak in Spanish it can sound like a problem but we didn't speak any and with a bit of help from Google translate we communicated without any issue. She was extremely nice in making suggestions for places to visit in the city and to allow us a late checkout the day we left. Thanks so much again!