I only stayed for one night (I was in town for work and wanted to spend an extra day in Madrid) and found the apartment to be perfect. Olga was very responsive and answered all my questions before arrival. She even had her manager meet me to give me the keys and show me around even though she could not be there herself.

The apartment is absolutely charming, and very secure (there are 2 outer doors to which you must have the keys to enter). There is a taxi stand and Metro stop literally 1 minute walk away, so you can easily find transportation. The area is safe and right next to a lively plaza with restaurants. Of course, it is also a stone's throw away from the Royal Palace, which is a tourist must-see. I had a delightful stay and was very sad to leave!