Great location--I cant stress this enough. Easy (a bit uphill...) walk from the train station and metro stop. If you are coming from the airport you can take the airport bus or the metro or the train and all these options take you to the train station and then you just do the couple minutes walk. If you want to take the train to Toledo--being close to the train station makes it easy also to spend the day in Toledo (which you should do...) Unlike a lot of buildings in Madrid, there is an elevator which is great if you have luggage. You are a quick walk to the Reina museum (and you can go for free in the evening) and an easy walk to the Prado which is one of the greatest art museums in the world. Restaurants and nightlife nearby walks also--although you could take the metro. Larger supermarket a one minute walk. Nice breakfast place across the street.
Large unit with large kitchen. Lots of space. Note--no door between kitchen and living room/bedroom. And it was quiet which is great.