Clara and Peps apartment was really comfortable for our 6 day stay at Barcelona. The neighborhood has everything you need, with shops and restaurants; and its really silent and safe. There are some small markets to do some grocery shopping, but there is a great market on Carrer de la Industria ( 2 blocks away).
You've got 3 metro stations near the apartment which are great to get anywhere you want.
Last but not least, Pep is a great guy. I would definitely recommend you staying here!