Check-in is very efficient and well-documented. The staff responds very quickly. I gave it four stars only because I never had personal contact with them. Everything is online. The main drawback is that, before check-in time, luggage can only be stored in a locker shared with other guests. Furthermore, there are no shared bathrooms in the building, but rather within each apartment. This meant we had to wait several hours at the train station to get to the accommodation just in time. The apartment is very nice, well-equipped, and in an excellent location. We recommend it, but plan ahead for check-in in case your arrival in Seville is before check-in time.