We had an absolutely wonderful time at Massimiliano's place. The flat is perfectly located just south of the Vatican walls. The view from the balcony is stunning.
We were pleasantly surprised that the flat actually has air-conditioning in both bedrooms as well as the living room, as the pictures suggested otherwise. The building is equipped with a lift. Although this didn't affect how much we enjoyed our stay, you could argue that the bathrooms need some touching-up at some point. Also for people that are not used to it, the mattresses might be a bit hard.
Massimiliano made sure to provide us with all important information beforehand and to help us get to the place safely when we arrived in Rome. He really is a great guy to meet.
When we come to Rome next time, we'll make sure to try to book this flat again.