I had a very pleasant 2 week stay in this apartment!
The place is fully equipped and situated in a quiet street surrounded by lots of family-owned restaurants, it definitely feels safer than other streets I've walked down in Madrid. It is also a 15 minute walk from Puerta del Sol and a few minutes from La Latina station.
The block doesn't have many other apartments in it (there are 6 doors spread out over two upper floors, the first two floors after entering the property don't have any doors on them) and the neighbours were quiet and friendly.
I stayed for 2 weeks, so had quite a lot of luggage to carry by myself. I wish I had paid more attention to the fact this place is on the 4th floor and there are no lifts! I really struggled to carry my suitcase up and down all the stairs! Please bare this in mind!
Overall I would recommend this place to others. I would rate it a 4/5 because I would've preferred a slightly more comfortable space. For me, the bed, sofa and kitchen stools weren't very comfortable and I think the space lacked a good place to sit and eat meals.