Above and beyond expectations. I can't say enough good things about the flat, the location and our reception by Mathieu.
Mathieu was extremely responsive and easy to communicate with. He even greeted us with some treats and small groceries which were very welcome after our long day of travel. The flat is extremely well kept with all the modern amenities necessary for a comfortable stay. The three bedrooms and layout gave us plenty of room and privacy if we needed it. Above everything, the building and flat are beautiful. Centrally located along Las Ramblas and just around the corner from Passeig de Gracia (luxury stores & hotels) so this area felt very clean and safe, with plenty to do within walking distance and several options outside the front door.
Being that this is a very busy/active area and the apartment overlooks Las Ramblas, you do hear quite a bit of the street noise in the bedrooms. This was not too bad as it was only cars and "white noise" at night, but if you are a light sleeper I would recommend some ear plugs. But otherwise everything was very enjoyable in this flat and the beds were comfortable. I would highly recommend a stay at Mathieu's flat to anyone visiting Barcelona!