Location, location, location. It was perfect for us, we're a family of six, with kids ranging from 13 to 18 and Poble Sec had something for everyone.
The apartment was nice, clean, well kept, it even has a Smart TV so we could login to Netflix and catch up with some shows one night.
Iris and the guys that checked us in were awesome. Super friendly and answered all of our questions.
The only thing to consider is the fights of stairs. We're an active family and it wasn't a problem, really. But if you're not in good shape, you might sweat a little ;-)
Awesome experience all around.