Fernando's place was smaller but cute and only a 13 minute walk to some really great sites (i.e. Plaza Mayor and the San Miguel Market). So in terms of relative location in the city, I'd say it was great!
Fernando provided a very informative (and thick!) packet with historic sites, museums, and restaurants listed. It also included suggested routes around the city. We found this very helpful for guiding our stay, as we only had two full days in Madrid itself. To fuel all this running around, he also had a bowl of breakfast muffins in the room that certainly came in handy.
I rated this down a touch for two reasons. The first being that the bathroom was *incredibly* small. We found this to be a bit of a challenge at times. With that said, this wasn't the first small bathroom we encountered on our trip and it may be the norm for apartments in such a big city. So this note is really only for people for whom a tiny bathroom is a complete deal breaker.
The other note was that this neighborhood is perhaps not the one I would've picked for two women traveling alone had I been there ahead of time. But in the end we never had any issues and, again, it was close to some great spots.
Overall, Fernando was a very nice host and we had a great stay at this apartment!