Elena's place is super clean and well-situated. Downside is there is no elevator; the apartment is on the 4th floor (lots of steps up, so be mindful if this would be a problem for you), but that wasn't an issue for me and Elena's friend was kind enough to walk my bags upstairs for me as I checked in.
Elena and her friend were also kind enough to store my luggage while I walked around the city leading up to check-in that afternoon. Check-in is quite manual, which would be my other suggestion for improvement and if you don't speak Spanish, you may need to use a translator app to communicate with Elena's friend who lets you into the building.
Minutes away (walking) from the Royal Palace and other attractions--wonderful location.