First things first: The apartment really is perfectly located to explore seville. All the hotspots can be reached by foot and you will stay directly in the nice old town. Everything fits the description and especially the roof terrace is a gem!
There was only one negative thing to mention and that is the noise level at night. Sure, you are directly in the old town so it is clear there is also noise. But there are lots of cars and scooters driving trough the narrow streets which made it hard for us to sleep well at night. There was also waste collection and street cleaning going on in the middle of the night.
Nevertheless we would recommend this apartment since it is really beautiful and well located. Just don't forget the earplugs.