Quiet street, but still walkable to to a lot of places. The flat was perfect -- 2 bedrooms, and a little balcony. Full kitchen. Great, easy place to stay.
Note: The neighbor smokes (so if you are sensitive to smoke it's mostly just the hallway.) The flat surprisingly doesn't smell like smoke. And the tv gets loud and you can hear it through the wall but we were instructed to simply knock on his door and he will turn it down. All of these things were brought to our attention prior to accessing the place and honestly didn't effect our stay one bit. I highly recommend staying at this flat on your next trip to Barcelona!