My wife and I spent a month in this fantastically located apartment. It's smack bang in between Plaça Catalunya and Mercat del Ninot. And only a few blocks from Passeig de Gracia. The posh neighbourhood is very safe and friendly with lots of dog walkers. Nearby amenities include a bakery, several small green grocers, a large supermarket and plenty of restaurants and bars. We highly recommend Casa Jaime for local food and the Japanese around the corner.
The apartment is spacious for 3-4 people. It has everything you need including a washing machine and good wifi. The small porch is an added bonus. Two double rooms and one small single so could sleep 5. However, the beds are not the best quality. The mattresses sink in the middle so two people sharing the bed will migrate towards each other. The flooring is also a bit creaky in places along the hall. Also, be aware of when someone is taking a shower because if you flush the toilet or use a tap that person will be scolded by very hot water! No aircon or heating in the bedrooms but we didn't need that at night as the weather was mild. Aircon and heating in the living room works great.
Overall we really enjoyed our stay and would stay here again.