The location is very convenient, it's close to the public transport hub (Plaza Espanya) and Plaza Major for lots of restaurants, shopping, etc.
The apartment was clean and we even got cleaning service twice during our 2 week stay.
The laundry room downstairs with sun umbrellas, some toys for kids and a space for our stroller was super handy.
Wifi was occasionally super slow (down to ±300kbps), but we didn't need it for work, so it was okay.
Some amenities in the kitchen area were a bit lacking (one small kitchen towel, missing corkscrew), but they addressed everything we raised very promptly. Communication was really fast and pleasant.
Airconditioning was working really great.
The apartment is not very sunny/bright and the balcony is on the smaller side, but that can be also a good thing during extremely sunny/hot days.
Perhaps the only slight drawback is the lack of seating in the living space area, where the apartment for 4 people could use one more armchair to actually chat around the coffee table comfortably without having 3 people sitting next to each other on a sofa.
Otherwise, all was great!