We had a great stay in Elviras cozy apartment! Communication went smooth. Location was perfectly fine!
The only fly in the ointment was that there appeared a loud buzzing every 20 to 30 minutes from a box above the main door while using the aircon. This made using the aircon during the night nearly impossible, but we cooled down the room in the evening and so we slept well in the end.
Nevertheless I can highly recommend the flat for a stay in Madrid!