The owner was very responsive and kind, typically reachable through whatsapp within several hours.
The room was large enough for 1-2 people and clean.
Nice neighborhood. Although it's in residential area, you can reach every tourist attraction in Barcelona conveniently. Subway stations are near (Les Tres Torres in 7 minutes walk and Maria Critstina 10 minutes walk), bus top is right in front of the apartment. Large supermarkets are within 5 minutes walk as well.
The room can be a little bit pricy especially for long-term stay, but location convenience / relatively quiet neighborhood and nice owner would compensate it.