Carmelo's place was ideal for our one night stay. 10-15 minute walk from almost all main attractions of Madrid. Loved the food market and Manzanilla bar. Can get a little loud at night because of the night life, but it was easy to shut the doors and they provide ear plugs as well (we didn't need them though).
Lots of good books on tourism and a nice spacious layout as well. You could stay for a whole week easily. Carmelo also was nice enough to let us check in a little early, which was nice! Highly recommend.