Check-in was easy. We had to pay an extra fee, but they accommodated a late check in due to the time of our flight. They met us at the apartment to check us in quickly.
The location is perfect to walk to Sagrada Familia and the area. It was an easy 10 min walk. There are lots of little shops, markets, pharmacies, and restaurants around. It was also very easy to hail cabs in this area (which is way easier and cheaper than Uber).
The apartment is clean and comfortable.
Pretty much everything we needed was provided (dishes, towels, blankets, toiletries, etc.) The apartment is safe, inside a locked building. The AC keeps the place comfortable on warmer days. Blackout curtains keep the bedrooms dark for sleeping in. If we ever return to Barcelona, we would absolutely stay here again. We really enjoyed it!