I have given this place a complete 5 stars in every category because it is well deserved.
First of all, the location is excellent, it is 5-10 minutes walk away from the city centre and that for me is perfect because it is not too strenuous if you are coming from the metro station (Sol). It is also a nice distance because it is still central Madrid but also not the exact epicentre where you might otherwise be affected by noise.
Second the apartment itself is wonderful. It is spacious and very well equipped with all modern amenities and equipment and also tastefully decorated. Even though we only stayed one night (I was visiting an exhibition at IFEMA), I much preferred Mattia's apartment compared to a cheap hotel because you just have so much more opportunity to relax in the extra space and enjoy the charm of traditional Madrid apartment rather with its balcony overlooking the streetlife below compared to hotel room that is not as unique.
Towels, soap, shampoo and all other manner of similar things, cups mugs, plates etc were provided and also the hot water was plentiful and had a good flow in the shower.
My only regret is that I didn't have more time to spend at Mattia's place and in Madrid - so be sure not to make the same mistake as me and to spend a bit longer in this apartment as it will surely enhance your stay in the city and be a welcome relief as a place to relax after you have spent the day exploring Madrid.
Lastly, please also remember that there are some rules to the neighbourhood where this apartment is and which Mattia has explained in his listing, and even though we came back late, because we were sensible, these rules did not pose us a problem . . in any case we should always be respectful of other peoples homes and neighbourhoods wherever we go.
Note for the drivers : there is paid parking for cars nearby in Plaza Mayor that you can find . . . however if you are unfamiliar with driving in Madrid, please be sure to check your vehicles emissions standards because some older cars (including mine) are completely forbidden to enter the central parts of Madrid. Luckily I discovered this before arriving so it was not a problem for me and I found the best solution was to park in Madrid Terminal T2 (which is next to IFEMA and if you book in advance, it is cheaper) and then take the train in which only takes 30-40 minutes.