Gilad's apartment was perfect for our trip. He was very flexible when our arrival time changed at the last minute, and his place was equipped with everything we needed - food essentials, laundry capabilities, and air conditioning, which was reliable and great to have. Despite being in a lively neighborhood, we heard no street noise at night and had no trouble sleeping. Gilad left a fan in the bedroom which provided nice background noise, and the sliding doors to the bedroom eliminated light in the early morning hours. Gilad was also an excellent host - he sent us restaurant and tourism recommendations and left a delicious bottle of wine for us when we arrived. We personally had no complaints, but for people with limited mobility or back problems, you must walk up more than 60 stairs to get to the unit, and the mattress is firm.
In terms of seeing Madrid, the unit is in an extremely convenient location. The metro trip from the airport was simple; Gran Via is only a few blocks away; and you are convenient to the metro lines that take you to Atocha rail station. But honestly, we took advantage of being in the heart of the city and walked nearly everywhere. The restaurant scene in Malasaña is excellent, too.
Overall, we couldn't have asked for a better experience. This was our first Airbnb abroad, and we would recommend Gilad's unit to anyone looking for a great place to stay in Madrid.