I had a good solo stay at the apartment in Seville. I think it would be good for a couple but small for more than that. It is located in the city center where most of the streets are for pedestrians only and you can walk to most everything. No need for cab rides from this location. Lots of food, bakery, small markets nearby. Please know that pedestrians will use the streets at all hours of the day and night and some can be loud during the night. For a light sleeper like me this was a problem, but for many people it would not be an issue.
The hosts were excellent and very accessible!