We stayed for one night at Mario's place. Although we didn't have the pleasure to meet Mario in person, communication was smooth, directions to the place from the train station were very specific and got us there without any problem, and there was a lockbox to access the keys. It was great to get lost exploring the side streets throughout Venice, but you can easily find your way back because it is located near the hospital. It was fantastic to be right on the canal to watch the boats go by. However, the only downside to that is the apartment smelled very musty and we had headaches, sneezing, and stuffy noses within a few minutes of being there. This is probably only because the place had been closed up due to the cold weather and infrequent guests in the off season. It's obviously hard to avoid damp conditions near the water. But if you have allergies, take this into consideration if you plan to stay in Venice for several days. Other than that, it was a pleasant stay. Thanks, Mario!