Super location, visitors can actually visit everything in Madrid (or at least the most known spots) by foot from this flat.
The host is super responsive, and the check in and check out process are super smooth.
The flat is well decorated as well.
Nonetheless, a few downsides need to be notified: because of the restaurants downstairs (so there is not much that can be done here), there is a constant food smell in the flat, and the humidity level is quite high as well, as the windows can't be open (because of the smell outside).
The bed is uncomfortable especially for 2 people and the apartment is not soundproof so we can hear the neighbours.
I would recommend this apartment for people visiting Madrid for the first time and staying 1-2 nights.