We can’t give this apartment five stars like we want to, because of something that is unfortunately completely out of the host’s control. Everything about the apartment itself was perfect: it was clean, comfortable, well-appointed, and very close to Gaudi’s Parc Güell. The host, Laia, was great to work with as well. We would also note that the reviews warning about the stairs are unfounded—the apartment is a normal (European) 2nd floor apartment (3rd floor in North American terms).
It does seem though that the apartment has a cranky neighbor who has a penchant for calling the police for noise disturbances. Laia warned us of this neighbor and we thought we would have no problem, as we are a very quiet couple and often get reviews commenting on our silence. However, during our stay the outside portion of the heat pump unit in the apartment developed ice and made enough noise to lead the neighbor to call the police, who came to the door and spoke with us. The neighbor had apparently complained to our host as well, and Laia contacted us quickly and courteously about the problem, which we solved immediately, but this was only minutes before the police arrived anyway. To us, the involvement of the police in this situation was unreasonable and negatively impacted our stay—no one wants to unexpectedly answer the door to the police while on holiday! We got the impression the hosts are working on the relationship with the neighbor, but it should be noted that even reasonable behavior resulted in a visit from the police with little warning. Again, other than the problem with this neighbor, this was a five star experience.