We stayed with 5 people at the apartment of Sebastian during mid June, which feels just about the right amount, 8 people can get a bit cramped but its doable.
The apartment is located in a nice residential neighbourhood of Barcelona with a few nice restaurants, grocery and shopping possibilities in walking distance, the way to the beach is an approx. 30min walk.
We enjoyed our stay in the apartment, however the furniture is a bit worn down and we only missed a few amenities to make the stay more comfortable/ useable, like stowage space in the bathroom and a parasol for the seating area on the terrace (which is quiet and very sunny from midday to early evening). We did not particularly mind, however for those who feel it's important; the rooms on the ground floor (two bedrooms and the bathroom) do not have much privacy. The stairway to the upper bed room and terrace is very steep and steps are small, so depending on the size, it could be difficult to get the suitcase upstairs. The kitchen was equipped well and had everything we needed.
Sebastian was very friendly and helpful and the responding time is very fast. Check-in and check-out went very smooth.