I really enjoyed my stay at Carlos's place. The location is amazing. If you're into a vast variety of amazing food options and local culture I cannot recommend a better place. Moreover, it is close to public transportation if you're going to go somewhere far. However, I didn't really use the Metro that much because the place is within a walkable distance to probably most of the city attractions.
Carlos is super friendly and gives quite good recommendations about the neighborhood and the city. I think I tried them all and I'm very glad I asked. Last but not least, the flat was quite good too. It actually has a very nice touch of style, and I enjoyed being in it. I felt at home the whole time. It was one of those stays where I wished I stayed longer and Carlos's place contributed to this feeling.