The appartment is very modern and well equipped. The check-in and check-out worked fine for me. The location is very central and you can do all the sightseeing by walking.
BUT the code for the main door is the same as the code to the appartment so everybody who has access to the building can also enter the appartment. They should definitely change that!! Also the other night the lock for the main door didn't worked so I had to open the door in the middle of the night because people tried to get in and it was pretty loud. All in all the appartment is poorly soundproofed.
For me it was okay because I only stayed for a few nights for a business trip and wasn't quite often in the place. If I am going to stay again in Sevilla, I would rather book a different appartment/room.