Sergio communicated clearly with me before my trip, had everything well prepared for a guest, and he and his flat mates were very kind :) I just had a bit of trouble sleeping because even with the fan it was hot (Madrid in August - not their fault!) and the bed is not too comfy. Then when I plotted the route to Terminal 4, Googlemaps said it would be 40+ minutes walking, so I had to take the metro (only one stop but costs 4.50€). But all in all, a nice stay with very nice people :)