We had a pleasant stay in this apartment. It is well equipped, cosy, bright and spacious. The neighbourhood is safe and friendly. It is next to the train station so you can easily get there from the airport (it's also the cheapest: with T10 tickets it costs you only 1 euro). There is a train always at 30 minutes and arrives to Sants in 20 mins.
The metro station is about 5 min away. You have small shops and restaurants nearby. The centre can be accessed easily by metro. But you can also walk to in 30-40 minutes.
Alex was welcoming us, he is a friendly and very kind person. He gave us a brief description about the city and the sights with some tips too.