I would 100% recommend Marcello's apartment, firstly he is an exceptional host! My mother came out to visit me for a couple of days last minute and he was totally okay with having an extra guest.
There was lots of thoughtful little touches like breakfast for the morning after and milk and water in the fridge. The kitchen is stocked with all the necessities to make a fabulous Italian meal to eat in the cute little garden with local Venetian wine!
He also left some tips on places to visit like making the effort to go to Burano which is a beautiful little island off Venice famous for colourful houses and lace. It was really worth it and I'm so glad he mentioned it.
The location is perfect, you're right next to the Vaporetto stop and from there you can get everywhere and to the airport quickly. It's also a lovely walk to Rialto Market, Piazzo San Marco and Venezia Santa Lucia.
The communication is excellent, quick responses and super helpful. I had some trouble with the door and he came very quickly to rescue me, in the journey to me I managed to figure it out and I felt terrible at wasting his time, but he was very gracious.
I really can't fault it. If you're planning a short trip to Venice you can't ask for a better stay!