Massimo and this apartment were absolutely great! Fantastic location near the Fondamente Nove Vaporetto stop. (Though a little tricky to find, as with pretty much any address in Venice. Massimo actually found us as we were passing right by the turn.) It was just far enough away from St Mark's Square to be a little quieter and less touristy, but still only a 10 minute walk from everything.
Massimo was an excellent host! He is very friendly and helpful. Beforehand, he emailed us a map with directions from the airport to the apartment. When we arrived, he showed us everything we might need to know about the apartment and then gave us a map and marked good places to eat, grocery stores and where the best places to wander around the city were. If we needed him for any reason, we had his cell number or we could walk up a floor and knock on his door.
The apartment was very comfortable with plenty of sheets, towels, blankets and soap. We made good use of the washing machine for our clothes and it worked great. (Though it did take a couple of hours to run and sounded like a jet engine... But that seems to be fairly standard in Europe. I wouldn't advise running it at night.) There are clotheslines outside of a couple windows with plenty of clothespins. (Plus an indoor drying rack if you don't feel like hanging your laundry out a fifth story window.) The kitchen is stocked with pantry staples like olive oil and salt. The apartment had everything we might have needed for our stay.
Hands down, this was the best place we stayed in on our whole trip. I wish we had been able to stay longer!