We very much enjoyed our stay. The flat is tastefully decorated with particular attention to detail. It is well located with two tube stations nearby (easy and quick access to the heart of Madrid).
We arrived at midnight and had some issues getting inside (the web link that was sent to us was not working), however, even though it was late, I was able to reach someone who managed to open the door remotely.
The only minor inconvenience was the rather high evening noise levels from our young neighbours (the bank holiday weekend and Halloween night may have contributed!) but they always dramatically decreased around midnight, which was fine.
I definitely recommend this place that feels like being at home and would be delighted to return.