The apartment is located in a great area full of tons of restaurants and a five minute walk from a decent grocery store. The Guggenheim museum is also within walking distance, and, because it's so close to the river, it makes for a beautiful run in the morning. It is also a 20 minute walk to the bus station, where you can catch the bus to the airport for 1,45 euros.
The apartment itself is very big, including a huge TV in the living room. The apartment is on the first floor, so there aren't too many steps required to get to it.
Gerardo is great! He is very available, responsive, kind, and willing to give suggestions about what to see in the city.
I would recommend this apartment.