The apartment is in great location- close to Sagrada Familia (15 minutes by walk) and Park Guell (30 minutes by walk). We were four people and we had enough space during our stay.
Indeed there is no elevator, so this needs to be taken into consideration as you need to go to the top floor.
We had a good communication with the people, who welcomed us.
The neighbourhood is great and nearby there are lot of places to eat, supermarkets and coffee shops.