Over all, we enjoyed our stay.
The apartment is very well maintained and very clean. It wasn't big but had everything we needed. It's nice to have a dining table and couch after spending many nights in hotel rooms. It was also nice to be able to do laundry during hot summer time.
The host was there when we arrived. She was very nice and told us where everything was in the apartment. She also gave us great suggestions on what to do, where to eat, and marked down everything on a map for us.
The location is convenient if weather is reasonably pleasant. It's not right next to all the historical sights but Seville is really not that big so you can walk to all the major tourist spots within 12 min. However, if you are visiting during a hot month like we did, then the walk to the main historical sights will be a bit tough unless you go VERY early in the morning. The cobble stone streets also don't help with the walk. There is no public transportation between the apartment and the main tourist area (probably because all the streets are very narrow). Thankfully there is a cab station very nearby so we were able to use it when we did not want to walk in 100 degree weather.