The apartment is beautiful. If anything the pictures don't do it full credit. The roof terrace is particularly fantastic with great views.
The neighborhood is less touristy than central Seville but still pretty and historic. It's a 15-20 minute walk to the cathedral and Alcazar but a nice walk. The metro parasol is close as are some lovely churches, monasteries, historic homes/palaces etc. There are good restaurants, bars, shops, supermarket nearby. Seville is truly beautiful and well worth an extended stay.
I would say you should be prepared to do some walking to get the most out of this location. The spiral staircase means you need to be mobile. The roof terrace could also be a concern if you have young children who can climb.
Communication with Elly was easy. All in all this was one of our very favourite air BnB stays.