Firstly, Rodrigo was an excellent host. Our flight times and arrival to Madrid were quite late in the evening, but the contact beforehand was superb, and meant that we were able to arrange for a friend to pick up the keys prior to our arrival. Otherwise, there were thoughtful touches left throughout the flat (such as coffees and biscuits etc) along with maps of the city.
The flat itself is in a good location, in a recently gentrified neighborhood, and all attractions and places of interest were no more than 20 minutes walk away.
There were four of us staying in the flat, and the space was ideal for our purposes. The only minor issue I would note is that the beds in the upstairs areas are singles, not doubles, but this was my mistake and in any event did not cause any problems. Additionally, ensure that any tall members of the group are not on the upstairs area, as the ceiling is a little low hanging here!
All in all, staying at the apartment really helped make this a great trip for us, and represents great value for money.