We had an excellent stay at Casa Del Mandarino. The house was large clean and comfortable and with some nice extra touches. For instance the walk-in dressingroom had a selection of pillows to choose from. The bed itself was really large and comfortable. We went in early September, it was still 37 deg so appreciated the aircon.
As for the location, it is on a quiet side street, very close to Maragall metro station. This made it convenient for getting to any of the Barcelona tourist attractions, and we even had a day out in Sitges. You just need a T10 travelcard. There are local bars and cafes nearby too.