We stayed for 4 nights at Laia's apartment. It is in a great location to explore the city. We could walk to most places we wanted to visit but the metro is close if you want to go further away. The apartment is very nice and clean, as seen on the pictures. The 2 terraces give plenty of space to enjoy the warm weather outside.
The WiFi was fast and stable which was also important for us, because we also worked partly during our stay. The apartment is quiet, even though during daytime you can here the street noise. But you are in the middle of a city, so that is normal. The bed was comfortable and we slept very well each night.
Laia is a very nice and friendly host. The communication was fast and exact. She sent us lots of recommendations for restaurants and places to visit and what to do in Barcelona and we liked the things that we tried from her list.
Overall it is a clear recommendation to stay while visiting Barcelona.