This apartment is really great. My wife and I stayed here for a week with our twin daughters who are 3 and it was perfect for us. It's quite large and felt like a really cool large loft in the middle of Barcelona.
About the apt: The living room face south on the street side and gets flooded with sunlight during the day. The rear of the apt is the bedrooms and 2 bathrooms where it's very quiet. Between is a huge kitchen area. The kitchen appliances and washing machine seem very new if not brand new. The high ceilings are quite beautiful with exposed wood beams and tile. The apt feels very spacious.
Some reviews I've read say the apt wasn't stocked with basic items. This was definitely not the case with our stay. Everything was provided: Toilet paper, paper towels, trash bags, linens and towels, dish & washing machine soaps, even some olive oil and salt/pepper/sugar. There were brand new knives and cutting boards. Most everything a cook would need was there. Hot water was plentiful. We didn't need A/C as we were visiting in March; the place was well heated. The elevator worked fine.
The location is excellent. The reason it's a good location is the neighborhood itself is beautiful and many desirable spots are within a 5-15 minute walk: El Born and the Gothic neighborhood; the Rambla; Arc de Triomf and the parks near it; Placa Catalunya and Passeig de Gracia avenue which is sort of the 5th Avenue of Barcelona. There is a subway very close and Placa Catalunya is no more than a 5 minute walk where one can catch the express bus to the airport (much cheaper than a taxi!). We were grateful to be about an 8 minute walk to the Santa Caterina market which is one of the great food markets of Barcelona but is far less crowded than the Boqueria on La Rambla. There is grocery store just down the street as well as a 24 hour small shop / bodega right next to building. There is also a good playground about a 5-8 minute walk from the apt. Architecturally the neighborhood is quite beautiful with grand old apartment buildings.
Gerard was a great host and very fast responses to any questions I had over email. (I never met him though it worked out fine.) Maria met us at the apt; she is nice but don't expect much more than a handover of keys and basic instructions.
In summary I would highly recommend this apt. If you are a family with young children I'm not sure you will find anything better though do note there isn't a tub in the apt. I would definitely stay here again and recommend it to friends.