I can't say enough about this place. A large group of friends took a cruise that ended in Barcelona and six of us (2 couples, 2 singles) decided to stay in town for four more days. Carles's place was AMAZING. It's within walking distance to the Gothic Quarter and Sagrada Família, and a few blocks from multiple metro stops. AND it's across the street from a large grocery store so if you want to cook during your stay (as we did), everything you'll need is at your finger tips. Plus there's a great little cafe at the end of the block where we got breakfast and coffee every morning.
During the day we were out and about, and in the evening we watched movies and played Nintendo Switch on one of big televisions they had. Both apartments have large living rooms and for those of us who wanted to crash early or just to read, they could walk over to other apartment. Christmas dinner was the only meal I cooked there and it required both kitchens, but I managed. And you're on the top floor of a commercial building so you don't need to worry too much about noise.
Just a fantastic stay all around and if we wind up in Barcelona again (which is quite possible) we'll definitely being staying here. Seriously, WE LOVED THIS PLACE.