We stayed in Luis's place for a week. The location is great! The apartment is right next to Plaça Espanya, where the airport bus drops you off. You can easily walk to La Rambla, and you can take a nice morning stroll to the Castell de Montjuïc through a beautiful park.
The apartment is clean and has a lot of room, at least when you're traveling as a couple. The kitchen is fully equipped, and the bathroom looks fairly new.
The host is great! Even though we never actually met Luis, he was very attentive. He contacted us before our arrival, and several times during our stay, to ask how we were doing and to give restaurant tips.
The only negative part of our stay were the neigbours. They were very loud, especially early in the morning.
But otherwise, we were very happy with the apartment, and with our great host!