The apartment was quiet and in a good location and extremely clean. The wifi worked very well and so did the air conditioning. I thought the entrance to the building was a bit old and dingy, but for the price the apartment was very comfortable for our 12 days in Madrid. If you and your partner are tall or large in size, the beds may feel a bit small as they are "full" not "queen" - that would be the only drawback I found.
Overall, we recommend this apartment for its great location and cleanliness.