We had great experience throughout our stay in the flat. It is nicely furnished, it has all equipment you would need for a week+ stay and is located close enough to the center but also at the heart of interesting (non-touristic) restaurants and shops. It is also convenient if you're with a car as there's lots of white zone parking places (free of charge) just 50meters away from the flat. Our host was kind enough to bring us more coffee capsules free of charge.
The only things I think could be improved are:
1) Host would only respond in Spanish and you have to use translator to make it work.
2) At first flat felt not very clean due to the fact it has very old (but beautiful) ceramic floor that is actually a bit worn out and looks dirty. We did full apartment cleanup after we arrived to only make it seem cleaner.
3) Noise coming from the main street is was pretty loud which wouldn't be a problem if we were not with a child. Luckily bedrooms are facing inner side of the building and are much quieter.
Overall our stay was great and the minor downsides are not something to put you off from booking the apartment.