There isn't a better location to stay than this place. It is in walking distance from everything you want to visit. We made our own coffee each morning, as we need that to function. The dish washer was perfect. As others say the apartment is quite dark. Perfect in hot summers and when you want to sleep, but you don't want to stay in the apartment too long as you'll miss the day light (the more than plenty lights are not the same ;)). Because the windows of the apartment are connected to the inside patio you need to leave the apartment to really get the day light. Luckily for you there's enough to see and do right outside.
The bed was a little harder than we anticipated, but the couch is incredibly soft and comfortable. There are enough cushions to make your stay more comfortable.
Nacho is very quick in response, gives nice advice for where to eat in Seville and is very approachable. Don't hesitate to contact him in case you need something.
We stayed a week (when it was quite rainy) and we enjoyed our stay very much. It was the perfect quiet getaway in the busy centre of Seville!