Carlos and Harrald's flat was everything we wanted. It was located very close to most of the sites of Madrid and if we needed to get somewhere, it was very accessible to transportation.
Gustavo greeted us and showed us around the apartment. A nice bottle of wine and a snack was left for us. It was a nice addition since we had just traveled so far. The was a huge book of recommendations and what was necessary for us to do with the apartment. It is nice to not have to guess on what the owner of the flat wants.
I would definitely recommend Carlos and Harrald's place. It's in a trendy neighborhood and is very welcoming to it's guest.
Again, mucho gracias, your place was a great choice in Madrid.