Wonderful apartment!
Be prepared to walk up ~3 flights of stairs to get to the apartment. The bed is tilted inward a bit, but is otherwise very comfortable.
It is a bit of a walk from the bridge to the city (where buses and cars drop off), but if you take a ferry it probably isn’t as bad. You have to walk a lot in Venice in general, so it wasn’t a problem.
The check-out time wasn’t as late as I would like, but was definitely reasonable, and I was able to find luggage storage for the day without too much trouble.
The host was super responsive, location is good, and check-in and check-out were easy and without problems.
The apartment was very clean, and there were several nice touches that made it feel as well-maintained as a hotel room (the soap was new in a plastic package; the towels were folded into swans on the bed; there were croissants, tea, and coffee for breakfast; etc.).
The sofa bed worked well.
Everything in the bathroom worked as expected.
The water was good to drink from the tap.
Overall, a great place to stay, and very well done for the price. I would highly recommend it.