This was a great find, the view is unbelievable and the studio very nice and clean. We never saw Valerio but everything went very smoothly, the neighbor greated us and we had biscuits, jam, orange juice and a bottle of water waiting for us on our arrival. This was very helpful as we didn't really need to buy anything (I brought some tea bags from home and the great pizzas restaurants did the rest. There is also everything you need in the kitchen if you want to cook). Valerio was also kind enough to let us leave our luggages in the appartement on our last day as our flight was late, this was also great!
The only down side maybe is that it is a bit far from the historical center (30 mn walk) but this was a real choice for us as we preferred to be in a more authentic part of town, near the Spanish quarter's little streets, just make sure you have good shoes! And the neighborhood is very quiet at night. Overall, a great experience!