Myself, my mum, my brother and his girlfriend all stayed in Angels apartment last week, and we were really impressed with both the location and the apartment itself.
It was very easy to locate, just a 2-3 minutes walk from the nearest Carre-four and the metro station. It takes about 5-10 minutes to walk to the top of La Rambla at the Plaza Catalunya. In terms of location, I really can't recommend it enough, its central to a lot of sites and generally the metro took about 10 minutes to get to La Sagrada Familia or the Picasso museum.
The apartment itself is really lovely, the beds are very comfortable and its quite spacey, its perfect for 2-4 people. Its decorated beautifully, is very light and the balcony looks out onto a pretty street view.
We were met by Angel's friend who was very helpful and showed us around the apartment, making us feel very welcome. There was also a pack that had a few recommendations of popular sites and places to visit which was kind.
Overall I couldn't really fault our stay - everything was so easy and laid back, and we really enjoyed staying at Angel's apartment. Hopefully we'll be able to come back soon!