We ( 4 girls) stayed in Madrid for 4 days (long weekend) and had a nice apartment at Helios‘ place. It‘s very very central and everything was within walking distance (sightseeing, delicious food, bars, clubs & shopping).
Everything was clean and Helios made sure we had a nice stay at his place. 24hrs check-in is amazing and we were even allowed to leave our luggages until midnight as our flight was early in the morning. I would definitely recommend Helios‘ apartment to everyone!