I stayed in September 2015. The website shows several pictures of the different locations that they have in Barcelona, so you are not sure which one you are getting until you arrive there.
They require an online check in which after several attempts I could not complete on my IPhone or IPad. They are reluctant to solve these issues by phone; they will encourage you to communicate by email. I ended up going to their office. There, Jay did my check in; he was very nice and helpful. Once you have the keys, you make it to the apartment on your own.
The building is shared with regular people, so they will encourage you to avoid being disrespectful to the neighbors. The closest metro station is Camp de l'Arpa. It was clean and beautiful. It has free Wi-Fi, AC, 1 bathroom with shower, a living room, dining room with a table for 4 and 2 bedrooms. One bedroom had a queen size bed and the other 2 twin size beds. The kitchen has a coffee maker, dishwasher, plates, cutlery and a welcome basket with tea and coffee.
I had an early flight, so for the checkout I just left the keys in the apartment. They booked me a taxi that took me to the airport. I will recommend you to stay here, I really liked it.