Stay Here!!!!
-- that's the TLDR "Cliffs Notes" version of the review.
Or if you'd prefer a review that's bit longer -- Stay Here...because it makes an excellent and affordable place in which to explore Sevilla.
On the location, it's an easy 15m walk from the Santa Justa train station, perfect for coming/going to Seville. Location is also about a 10M walk from places to unwind like the Alameda Hercules (for bars/restaurants) and the Riverfront/Triana.
As for the apartment and its hosts -- the place is very comfortable and its hosts are attentive, considerate, and FAST in their responses to any questions/concerns you may have...
All of which leads to the conclusion, in case you missed it above....
STAY HERE!!!