The apartment is in a great location, lots of access to public transportation, bus or metro, there is a small grocery shop right next door and a KFC and Burger King if you want fast food. The neighborhood was quiet and safe, we had no problem walking home at 9-10 pm with a 2 year toddler.
The host was very accommodating and knowledgeable of the area. Wifi was fast and we had no issues with it. We came during the winter and the apartment was a bit cold for the first day. The next day it was much warmer one the heat was running.
You can hear some street noise in the bedrooms, but this is a city, I would expect that. This is an apartment so you will hear noise from the hallway and next door neighbors, but you could not hear it in the bedrooms. There is a small 3 person elevator to help you get up and down. It fit our small umbrella stroller perfectly. Also the apartment very typical, European style and sized, don't expect American sized amenities.
From the apartment, it was a quick ride to Castell de Montjuic, Mercado de la boqueria, la rambla, the beach, casa batllo, and La Sagrada Familia.
I highly recommend staying here with a family.