I am surprised by our experience, given all of the extremely glowing reviews. But all I can say is that photos can be a bit deceiving.
I really dislike giving negative feedback, but we were frustrated by a number of things, the saddest of which was the fact that bleach was left on top of the washing machine looking very much like laundry detergent, so we ended up ruining a bunch of clothes. We were met at the water taxi by the host's assistant, who escorted us to the apartment and "explained" things about the apartment to us in Italian (I presume) when we speak zero Italian. We did our best to communicate, but it was really tough. I hate to sound like the "ugly American," but if the host knows that you're English-speaking but doesn't even provide an instruction binder or anything with English explanations, that is difficult. The assistant did not show us the washing machine when we arrived; and if he had, he might have noticed that the bottle on top of the machine was bleach and not detergent, which could have saved us a lot of money. When I contacted the host about having difficulty figuring out how to start the washing machine, he sent his assistant over (but it was while we were at dinner). That is when he alerted us that the bottle on the machine was bleach, not detergent. But it was too late for our ruined clothing because I already (unknowingly) had put "bleach" into the load.
The apartment is really huge, and it is in a good location, walking distance to both San Marco Square and Rialto Bridge. But the photos do not show that the furniture (which once was pretty glamorous) is showing a lot of wear (stains on the cushions, etc.) I didn't think the bed was very comfortable at all, making it difficult to sleep. Also, the first night, I had some tiny insect buzzing around my head and in the morning, both of us had bites on our faces. We were awakened bright and early by the loud crowing of gulls, which is somewhat expected when you're around so much water but difficult when dealing with jet lag.
While the apartment itself was fairly clean, there is a gate going into the courtyard where the building is located, and there was trash presumably set out for pickup. That was unpleasant to walk past several times, but even after it was gone, there was spillage from the trash still remaining. One evening as we were going out for dinner, a rat ran from that area into another corner. Gross! There was also dog feces in that courtyard area. It should be noted that the steep and somewhat uneven stairs up to the apartment could be difficult for some guests, particularly with luggage.
The second morning, my husband was taking a shower when the water suddenly turned cold. We waited an hour and checked it before I tried to shower. It was still cold. We went out and walked around for 90 minutes, came back and it was still cold. So I went without showering and it was on the day we were leaving, so there wasn't time to get it solved.
On the plus side, the location is great and the apartment is very large. There is a hair dryer built in, and the radiator in the bathroom kept it nice and warm.