The apartment is very well localized, the neighborhood is great. The kitchen is small but well equipped and with some cakes and coffee which is a really nice touch.
The photos make the apartment seem bigger and brighter than it is. The living room windows looks on an "internal" skylight, with a view on the interior of the building. And it's not really well isolated for the sound.
We had some issue with the hot water which was lasting around 4 minutes, so it's not easy to hot shower, especially if you are not alone. Also some stuff in the bathroom were broken (the vanity, so don't put any weight on it) and the secondary (upper) shower. I understood that the apartment had suffered of unrespectful tenants.
So when you arrive, a deposit is requested (100€ for us), which we recovered easily when we left but I did not see that in the announce.
So it's a good place if you have intention to spend most of your time outside to discover Madrid.
And the hosts were really convenient for the arrival