That is one of those amazing experiences you are lucky to have with airbnb.
Mr. Giovanni was very nice to my family, he waited for us at the vaporetto stop and walked with us to the apartment. He showed us all the details and gave us good advices about restaurants.
He is a local person, born in Venice, so this is the right person to give you advices.
The apartment is better than in the pictures. It is extremely clean, smells good, well equipped if you want to cook, it has a bathroom and a toilet, it is spacious, and the location is amazing. Near supermarkets (where locals shop), but a 10 min walk to piazza San Marco. I would only stay in this apartment when i go back to Venice.....I strongly recommend it!