Sergio’s place is very stylish, exactly as shown in the pictures. Location is great, walking distance to lots of sites - we actually walked to most of the places. There is a restaurant right next to the place called TOGA, definitely recommend to go if you’re staying - one of the best food we had in Madrid!
As mentioned in other reviews, the place isn’t very soundproofed. Won’t be a problem if one doesn’t get bothered by noises, while for light sleepers it might be an issue.
In general we enjoyed our stay at Sergio’s place and would recommend to others.