I strongly recommend this apartament!
Franc is a great host, kind and organized, he was very understanding about the late checkin and checkout and responsive to our needs. He knows the area and could recommend us some nice, delicious bites in the area.
Also, the space checkes all the things you might look for in an accomodation: it is clean, very well equipped (from laundry washer, laundry detergent, dish washer, well equipped kitchen, paper towels, iron and ironing board, hangers, enough furniture for clothes storage in both bedrooms, to even an umbrella).
It's quiet, traffic is far enough not to hear it, there's at least one cafe across the street, supermarkets, restaurants, a kebap and at a max 5 min walk the Arena where you can find a bigger supermarket, stores for shopping and restaurants on the rooftop.
Access from the airport is very easy. We took the bus A2 (5.9 euros) that stopped in Plaza Espanya, at 2 min walk. Also, in the same square there's the subway station that takes you to the historical center, but I would recommend walking that 20-30 minutes walk, because most of the way to the Gothic Quarter is pedestrian and you can admire that incredible architecture of Barcelona.
The only thing we regret after this 5 day experience is not staying longer in Barcelona, we really loved the city and the apartment :)