Sergio's place has a beautiful view over the city, is close to the metro, and has any number of great places to eat. The doormen are also very friendly and helpful, allowing us to store our bags with them on our last day. You do hear a bit of a traffic noise, but you're are largely removed from it with the doors/windows shut. Only minor issues with communications which were quickly sorted out, the rest of our stay was perfect. Would definitely recommend Sergio's place as a great base to explore Mexico City!