I don't know where to begin with this place, other than it left me with very split opinions on whether it was nice or not, so I'll just separate below.
The Good: It is spacious enough with plenty of storage space in the bedrooms, as three adults we had no problem with fitting luggage, carnival costumes etc. Most of the furniture looks quite new and the place was very clean. The location is also not bad, as there is a quite big street nearby with restaurants, supermarkets and more or less everything else you might need. It is not very close to the central part of Venice for walking, though it is easy enough to take public transport and there are a few boat piers around. The area itself is quiet, so if you want to avoid the noise and commotion of the center of Venice it's perfect.
The Bad: The bathroom. I got the impression it was small from other comments, but I never realized it doesn't close properly. There is some sot of plastic screen you can pull instead of a door. It makes a horrible noise when pulled, so I'm not sure how the host is concerned about noise when pulling this is enough to wake up a few floors around. It also doesn't isolate whatever is going on in the bathroom from anyone else, so any aspirations for privacy won't work. Other than that I thought the size of it was not terrible, it was more that it was lacking any shelves to put things on, which made the little space available around the sink very crammed. The kitchen area is quite small as well. Finally I had a problem with the mattresses, as they were old spring mattresses and were sinking quite a lot, so my back wasn't too happy after a few nights.
The Random: Communication with the host was not always easy and we only finally got instructions on check in about two hours before we were there. They were clear enough once we got them, however we were quite worried by that point as the host was refusing to pick up the phone and hadn't written in three days. There were some quite random demands as well, like sending pictures of our IDs and leaving the city tax in cash on the table, which had me a bit worried. At least the tax is mentioned in the description for the apartment, but if it's just a rule that you need to pay it wherever you stay in Venice, I think it should be included in the payment you send through Airbnb itself. Finally some of the consumables like coffee and soap were left in rather small quantities for 3 people for five days (4 coffee pods + 4 single use shower gels), though the host did say that he could bring more at some point if we needed them.