We stayed 4 days in Carlos flat and had a great time there. The location of the appartment couldnt be better. You can walk to the beach in 15 minutes. To get to the center of Barcelona you can take the tram. The Station is just a 2-3 minute walk away from the hostel. Supermarkets are just arround the corner too. There aren't much tourists in Carlos neighborhood, which we also liked a lot.
Carlos and his roommate are very friendly and open minded. It was a pleasure to live there.
Thanks to Carlos suggestions we saw some really cool things we normaly wouldnt have. He gave us a map covered by notes telling us where to go, what to visist and how to get there.
We recommend Carlos flat to everyone visiting Barcelona!