Considering how expensive accommodation (particularly hotels) are in Venice, Arianna's place is a great find.
The apartment is walking distance from the Santa Lucia train station. However, you must take care to follow Arianna's directions very closely, as the first time you arrive it can be rather difficult to find (and Venice is notoriously easy to get lost in).
The room itself is located in a three-bedroom apartment. All three bedrooms are rented out on Airbnb. This was not a problem for us as the other guests were quiet and respectful, however this might not be the case always. Each bedroom has its own private bathroom. Guests can use the sink and microwave in the kitchen but are forbidden to use the stove and oven for cooking.
The neighborhood is very quiet, but is a short walk to shops and restaurants, and also to the water-bus station.
Overall, we had a good trip in Venice and no troubles with the room. I would say if you are looking for something romantic/private, or something self-contained for a longer stay, this apartment is not for you. It was a good affordable option for us (two friends) for a long weekend.