Let's get one thing out of the way: this is a fourth floor walk-up apartment. That said, if a climb does not bother you, it is a fantastic AirBnb. The space is bright and clean with tasteful decor and it's clear that the apartment was recently renovated.
In terms of location, the apartment itself is tucked away on a quiet street in a neighborhood with many lovely tapas bars and cafes. We found that it was perfect for exploring the museums and was a very short walk to the Reina Sofia, as well as to the Prado and the Thyssen.
Javier was communicative and helpful. He was accommodating and flexible with our check-in and check-out times, which we were very appreciative of. We would certainly stay here again or recommend to friends visiting Madrid.