Arianna and I had been corresponding up to 1/2hr before I was due to be met at the apartment to be given the keys. When I got to the apartment (at 6pm) I was told by an agent that Arianna was actually at home and so I could not stay in the apartment.
I would not recommend booking to stay at Arianna's because I think the risk of her cancelling on you with no regard - with no warning - is too high.