We really ejoyed our stay at Ana & Rafa's place.
The flat has everything you need, it's very spacious and the beds are very comfortable. The location is great, the tube is just 2 min walking from the flat (easy to go to the main Barcelona sightseeing locations), less than 5 min walking to Aerobus (bus connecting to airport) and less than 10 min walking to Sants train Station (we did a few day trips to the beach from there).
Ana and Rafa are very friendly, easy to communicate and very responsive. We had a issue with the coffee machine and Rafa came back with a new one 2h later!
I would highly recommend and definitely stay again!