This is an amazing apartment in a wonderful location with the best imaginable host. I agree with all the good things others have said so will concentrate on my experience. First I am a lifelong insomniac. However I had no problem sleeping at all and the window shutters created unusually complete darkness. However I do use wax earplugs if I think there might be a problem so I would advise taking some if you are ever sensitive to noise. But it is no noisier than any lively city area and not irritating.
Secondly I got ill while I was in Seville and Martin did everything he possibly could to help which was just so helpful in the circumstances. Truly a lovely guy!