Carlos's place is everything you could wish for while staying in Madrid. Carlos was kind and very communicative. He contacted me prior to arrival and a couple times during my stay to make sure I was comfortable and that everything was working well. He's the perfect host. He provides a welcome book with all the functional information you need, as well as tips and suggestions for your time in the neighborhood. The Lavapiés zona is bustling and beautiful with plenty to do and tons of local cafes, bars, and restaurants. Its maybe a 4 minute walk to the Lavapiés metro stop and maybe 6 minutes to the Embajadores stop. From either line you can connect to anywhere you want to go in the city, as well as Cercanias trains and the Renfe stations at Atocha and Chamartin.
The apartment itself is cozy and comfortable with two balconies, two bedrooms, and a full kitchen. It was the perfect base from which to explore the city and also a comfy place with flawless wifi for the work I needed to get done. I would recommend Carlos's place to everyone and I hope to stay there again myself on my next trip to the capital.