We had a really nice stay at Betty's place.
The appt was super clean and provided with all basic facilities and more.
The location is not in the touristic center which is a great advantage because it's a calm area and everything is still doable by foot. By this you will also see more of the authentic city.
A disadvantage were the thin walls and the dogs in the building. We woke up everyday around 7 o'clock because of our neighbours getting up and down the stairs or by the barking dogs in the hallway.
Communication with Betty went very smoothly. We got to leave whenever we wanted since there were no new guests on the same day.
Overall a very nice place to stay in Venice.