Barcelona is an amazing city and we will definitely be back one day. Zhao's apartment is outside of the center, so very quiet friendly neighborhood. The best part is the metro is right outside of the apartment that gets you to the beach or the center in about 15-20 min.
The apartment is updated on the 11th floor. We are a family of 6 so there is definitely enough room for us to sleep but we were a little crammed in the living room. (Not enough space for all of us to sit) and not enough space for our clothes. The washing machine didn't work very well but there is a brand new laundromat 1 block away that I used.
The wifi worked great. My husband would use it for work while the kids watched Netflix on our Apple TV we brought with us.
Zhao was a great host and made sure we were doing good throughout our month stay.