I would definitely recommend Ernesto's place. I came with my family and we were a total of 4. We slept comfortably and were able to visit all the sites in Madrid by walking. Granted we are a walking family and are willing to walk 20-30min :) Otherwise there is easy access to metro, buses, and taxi. No taxi ride was very expensive from Ernesto's area to the major sites we saw. The apartment itself is very modern, clean, and comfortable. Two single beds, a large sofa bed and a main bedroom with a good sized bed as well. There is laundry and wifi on site and a nice kitchen. Communication was easy and we had no problems. Definitely recommend.