If you need a place to stay that is walkable, convenient, and safe, I'd highly recommend Lola's apartment. She is a great host that is sensitive to your needs. I had a simple breakfast with coffee, juice, and bread with jams provided every day. Lola is very considerate! :)
For anyone sensitive to noise, I'd recommend the other room available. This room had a window close to the elevator so you can hear people using it in the middle of the night.
100% would stay again during my next trip to Barcelona.