We had a lovely stay at the rooftop apartment. It had a terrace/deck where you can spend the evenings which was a bonus. It is a communal terrace, but nobody came up during the time we were there. It has all the amenities listed and we were welcomed warmly by the host on the first evening. The place is close to Sagrada Familia. We normally used the L5 line from the Sagrada Familia station. It is also close to supermercados if you want to buy ingredients and cook. The apartment is close to pretty much everything/everywhere. Walking is our preferred way to explore the area and the district doesn't disappoint. The neighbourhood also feels safe. We highly recommend staying here.
The only thing to consider is that it is a rooftop apartment with no lift—it didn't bother us since we enjoyed the views from the top and we are used to buildings having no lifts.