I highly recommend staying in this apartment. The apartment is in a quiet area of Venice, mostly residential, but with options for restaurants and cafes. We loved it because it allowed us to have a quiet space to come home to, and gave us the chance to have an after dinner bottle of wine by the canal without the Venice crowds. It is ~20 minutes to get to St. mark's square on foot, but if you're okay with walking, this apartment is a great deal! You see gorgeous sights along the way, and some good places to grab a cappuccino. The apartment is the perfect size for two or more, and very clean. The apartment is about 12 mins from the bus station, which is the best way to get to Venice airport.
Caterina's daughter was incredibly helpful - she met us at the train station when we arrived, told us about Venice, and provided a SUPER useful guidebook that she made herself with restaurants, art exhibits, and useful logistical details about Venice.