The apartment is rented by an agency which I didn't expect but is not itself a bad thing. The check-in process was straight forward, Quique was responsive (I never met Leslie) and the walk from the agency to the apartment is not bad. Actually all the communication was impressive (see below). Check out was as simple as you can get; just walk out and leave the keys behind. Very easy.
The view is of course one of the main drawing points of the apartment and it is as great in real life as in the pictures. The apartment itself though is not up to par; everything worked fine but the furnishing is outdated and even when cleaned it feels dirty and grouchy. We had an issue with the toilet in the main bathroom as the refuse pipe (which went out the back of the toilet, not directly into the floor from the bowl) was leaking. To their credit, and we contacted them at 23:00, they got back to us right away and sent someone to patch it in the morning. The second bathroom, which is just a toilet, is functional if a bit awkward. We could not figure out how the door actually worked and got in on pure luck each time although I'm willing to say that one is one us just because everyone in the building seems to have similar locks. We still had a great time in Barcelona and the apartment is near the metro and bus stops so it's easy to get anywhere you need.