I've marked this as accommodation as "good as expected". I had no reason to doubt Victor's ad. It was a splendid flat.
I've been to Madrid a few times before and have generally stayed on the north side of the city, so this was my first experience of this area and I have to say it was pretty good. Local cafes and bars were friendly, as were the local people. The apartment is perfectly situated for the station and the station is well connected and all the places I wanted to get to were easily accessible.
Victor was quick to respond to all of our enquiries and gave good advice on the use of the Metro and purchase of travel cards. I usually walk everywhere as it's the best way to experience a town, but we had a lot we wanted to do this trip, so although we did a lot of walking in the centre of town, the ticket was money well spent as we could get to the localities we were visiting with ease.
Thanks for your hospitality Victor!