Constantine's apartment is nice, well-furnished, and all the appliances meet our needs. She is always available to the messages even out check in situation is a bit complicated.
The location of the apartment is fairly nice. It didn't cause any trouble when we are traveling through Madrid. About 2 minute on foot to Metro station. No more than 20 minutes to Sol. A supermarket is accessible nearby to 21 or 22 pm.
I strongly recommend Constantine's apartment to those who would like to experience life in Madrid. Definitely visit here again if I come back to Madrid.