We were a party of 3 adults and 1 child and we felt comfortable in the flat. However, if you're more, the remaining rooms are very small, as shown at the pictures. Also, the flat is rented by an agency. While we didn't mind, it might be an important information for someone who looks for a special relation with the owners. It's about ~25 mins walking from La Rambla but the metro is few minutes away. The living room and the main bedroom give on the street and hence, there are rather noisy but it was OK during night.
The basics (tea, sugar...) are not provided.
But overall, the flat was very clean and comfortable and we had a great time in Barcelona.