Zane's apartment is really nice for a short stay for 1-2 people - a weekend exploring the city or a business trip. It's very nicely decorated and equipped for comfort. And the host was very accommodating with check -in and check-out, etc.
We stayed in the apartment for almost 2 weeks at the height of summer with 2 small children after an apartment we originally rented turned out to be unlicensed and we had to leave (Barcelona is cracking down hard on unlicensed rentals, so beware). For our purpose (summer holiday with kids), it was less than ideal.
Zane's apartment is located on an extremely busy and noisy road. It IS equipped with double glazing and air conditioning, so technically you don't NEED to open the windows. But it's quite hard to ventilate without doing so and Barcelona in summer is quite humid and the air gets stale. With the windows open the noise from the traffic is extremely loud.
The living room side is bright as seen in the pictures (those two windows are the ones facing the noisy road), but the rest of the flat is quite dark. The second bedroom is more of an alcove off the corridor, it has no windows and no door. Well, it HAD a window onto a light well, but the light well had an elevator retrofitted in it, so there's a window onto the inside of the elevator shaft...
The third issue we had with the apartment: a lack of (proper) doors. Like on the shower/toilet. Yes, it makes the apartment feel very spacious, but there is ZERO privacy. There IS a door on the master bedroom, but if you close it, you will no longer get the benefit of the air conditioning which is located in the living room...
Besides those three issues, it's as described and shown on the photographs.
The area (apart from the extremely noisy road) is quite nice and typical of Barcelona. The Sagrada Familia is within walking distance, as is Passeig Sant Joan and (at a stretch) Passeig de Gracia. The accessibility by metro and bus is great too and there are several supermarkets and restaurants within 200 meters.