If you want to feel like you're staying in the real auténtico Madrid, stay here. It's in an old neighborhood on a wonderful quiet street and is within easy walking distance from Sol, the Plaza Mayor, the Royal Palace, and both the Prado and the Thyssen art museums.. Even Retiro Park was only a 15 minute walk.There are dozens of restaurants, tabernas, bars, etc., within a 5 minute walk. Best paella we (I was visiting my daughter) had was right across the street at the Arco Pinoy. Maybe the best sangría as well.
If you're not a walker, the metro system is very good and will get you close to almost anything.
The apartment itself was perfect for 1 or 2 people. Clean, comfortable, lots of necessities like soap, shampoo, detergent, coffee, etc., were supplied. Kitchen very well equipped, but don't eat dinner in the apartment! Go out every night!
Check in and checkout were a breeze.
You would love staying here.