My partner and I really enjoyed our overnight stay at Jorge's place. As per his instructions, we contacted him the day before we arrived and his assistant reached out to me via Whatsapp. We arrived a little early (about 15 minutes) to the apt and his assistant was waiting for us on the street. He gave us a walk through of the apartment, reviewed the house rules for us, and reminded us to contact him if we needed him for anything.
The place, which has a full sized bed and a sofa bed is very cozy and perfect for two people; although it may be a little tight for 3+ people. The apartment was very clean, with the exception of a few marks on the walls (nothing too bad). There is a fully functioning kitchen with a table and some chairs. Since this is an older building, you cannot flush the toilet paper and you have to put it in the trash can (I know some people, especially from the States, are not used to this). The place has a remote controlled AC unit, but Jorge's assistant told us not to use it for more that 1.5 hours, which seemed odd. Luckily for us Madrid was not too hot during our stay.
Please, be aware that this place is very centrally located but it is on somewhat busy street and it may not be the best place to stay if you are a light sleeper.
All in all, if I return to Madrid, I would love to stay here again.