We stayed for 5 days at Aga's apartment. Aga organised taxis for us from and to the airport for around 35 euros and that was a really nice and easy entry and exit to the city. Excellent taxi drivers too. The location of the apartment is excellent. In a safe neighbourhood with a walkable distance to La Ramba (shopping district). There is also a lot going on around the apartment building - we arrived on a Sunday evening and we still had 2 small stores open nearby and a few restaurants and bars (it was beautifully lively!)
The apartment building itself also appears safe. It is a typical apartment that one would find in Barcelona, so has a different feel to Western apartments in the UK/USA/Canada. The apartment is made up of 2 bathrooms (one more well-equipped than the other). A basic kitchen. 1 living space with a couch and 2 bedrooms (or at least that's how it was organised for us - as we were 2 people). On initial glance, the apartment appeared very dusty and marginally unclean. However, we soon realised that it was purely because the apartment and its furnishings were old and it had been cleaned - so keep this in mind when arriving.
The bedrooms were nice and simple - definitely sufficient. The sofa bed is adequate. However, there is a part of the sofa where it transforms into the bed and it can be quite uncomfortable (around the upper rib region). If you're not used to hard surfaces, I would suggest getting some extra blankets for yourself for padding.
My favourite part of the apartment was the balcony coming off the main bedroom. If you're from countries where balconies are not common, this is beautiful. I often sat here in the nights writing/people-gazing or even snacking and it was excellent.
Overall, I would definitely return and recommend this apartment.