Excellent location, nice apartment!
We stayed here for a week with our 1-year-old. In addition to lot's of cafes, restaurants and shops close by, there are three really nice play grounds within 200 meters from the front door. The elevator is smallish, but our travel buggy fit in nicely. The host provided us with a travel bed and a high chair for our kid with no extra charge, which was really nice.
We had some issues with hot water, but the host fixed the problem quite quickly and was really fair in compensating our inconvenience. All in all communication and arrangements with the host went smoothly.
On the down side, the sound proofing of the walls is quite poor, as it seems to be all around Barcelona. This was not a big issue in the master bedroom facing the street, as the street is surprisingly quiet during nights. However, in the smaller bedroom the elevator alarm could be heard really clearly, and, as the window in that room is facing the staircase where lights are on all night, the room is quite bright during nights. Luckily our child is a good sleeper, so she didn't mind!
And one small point still: be sure to close the elevator doors properly (not carefully, you really need to bang them to close them). The building janitor came ringing our door bell twice claiming we had left them open... It seems he doesn'tlike turists that much, but we managed to get him on our side by continuous smiles, thank you's and greetings. :)