I stayed at Carlos´place for 8 nights and will hopefully get to stay in his apartment also on my next stay in Madrid. The apartment is just as shown in the pictures and very clean and well equipped. Internet was working superb the whole time (I find that this is often a problem in other apartments) and he also has some "English-speaking" channels on the TV which I appreciated very much.
The apartment is only a few minutes walk from the metro station that quickly takes you into the city centre, but is also itself close to shops and restaurants. The shopping centre at Nuevos Ministerios is also only 10-15 minutes walk.
Carlos is the perfect host. I didn´t meet him in person, but we spoke on the phone and he was always immediately available on WhatsApp. He even texted me to see if everything was ok when he hadn´t heard from me for some days (because everything was more than ok!). The concierge Juan is also very nice and helpful and showed me the apartment when I arrived. Also, Carlos´had bought fruits, yoghurt and juice for my first breakfast and this is the first time I have experienced this on an Airbnb stay.
In short, I highly recommend this apartment both because of the apartment itself and Carlos the host :)