This is a gorgeous apartment in a very convenient location for hitting many of the "classic" first time visitor attractions in BCN. 10 minute walk to the heart of L'Eixample and 10 minute walk to La Rambla. Road noise was zero issue despite being located on a busy thoroughfare (Ronda de la Universitat), though the subway is fairly noticeable as a low rumble every 10 minutes. However, the subway sound was never an issue for us.
The apartment is exactly as it looks in the pictures, with the enclosed balcony being a highlight. We spent hours every day in that balcony enjoying wine and watching the world go by. There's also an open air balcony and the windows in the enclosed balcony completely open, which would probably be an excellent feature in the spring or fall. The apartment came stocked with delicious teas and a selection of wines, the latter not being complimentary but available at a very competitive price. The bathroom had an endless amount of luxury soap, shampoo, and conditioner, as well as more towels than you could ever hope to use in a week's stay.
Overall we can't think of anything we would have changed. This is an excellent stay, particularly if it's your first time visiting BCN.