For an absolutely unique experience, sleeping in a former chapel, Alessandro's place cannot be beaten. The apartment is a 15 minute bus ride from Piazza San Marco. If staying over a holiday (as we did over Easter), bus service can be spotty.
You should ask Alessandro to explain what he knows about the chapel where you will be staying as this will add to the experience. We went to bed looking up at a wall painting of the Annunciation - wow!
Please note that you will share the kitchen and washroom with the host and with guests in another room. This is generally not a problem but if everyone intends to use the shower or brush teeth at the same time, this will require patience and coordination. When going to the washroom, it is necessary to go through the living room; though the host is very discreet, so this is not a problem. Alessandro will make sure some space is available in the fridge to store essentials. We stayed 3 nights, which was perfect.