Excellent flat in an interesting and characterful building and area. Adequately equipped for eating in, but lots of restaurants and take-aways in the vicinity, including a 24 hour Carrefour supermarket round the corner.
Very near the Metro, but also easy walking distance to many of the main sights of the city, including the Palace. Reina Sofia and Retiro Park.
Check in was very simple using the mobile phone, and keys available after.
Aaron was very helpful, and responded quickly to any enquiries.
I'd certainly go back!