The apartment includes everything needed for 1 or 2 people for a stay of a few days, although we were only there one night. The bed is comfortable, the kitchen easy to use, and there are few stairs to climb (it is a basement apartment). You can walk to the historic area of Madrid relatively easily.
We rated it 4 stars because of difficulties with the bathroom. It is small - even more so than that which is usual for the EU. The shower head was loose and sprayed water over the doors when it was turned on and the water temperature was very difficult to adjust. The sink faucet sprays at very high pressure splashing the person in front of it. Finally, the wall-mounted toilet tank drips onto the person sitting on the toilet.