We were disappointed with our stay in this apartment for a few reasons. The late check-in fee is charged for anyone arriving after 9pm, which was when our train arrived in Barcelona. Most other airbnb hosts have had no issue with later check-ins, or have set up a lockbox system. The apartment had a weird smell that lingered for our entire stay. The floor was also quite dirty when we arrived - enough so that we had to vacuum. Note also that there was no AC in the bedrooms - only in the living room.
That being said, the apartment was quiet and had a great location (literally across the street from the metro stop).