I want to be fair to this place and its host, but also offer advice from experience.
First off, we loved the proximity of the apartment to the train station. Check-in was made very easy by Giuliana, and she offered LOTS of advice on activities, restaurants, and places to see in the area. She was very prompt with communication and seemed to try her best to make things as comfortable as possible.
That being said, the layout of the apartment was not as advertised. The bed was repositioned into an awkward spot from the Airbnb pictures and replaced by the couch. My guess is, this is due to the poorly functioning air-conditioner. It must not be venting outside well, because instead of cooling the room it made it warm and stuffy rather than cool and dry. Also a huge icicle fell from the air conditioner onto the floor and startled us greatly (Another indicator to me that it is not venting properly). We would have opened the window for air, but after a LARGE hornet flew into the space during dinner, we didn't want to risk having another dangerous pest in the studio. We were left feeling trapped and quite uncomfortable sleeping in such a stuffy environment. After spending a hot day in Venice, it was very disheartening to come home to a studio that felt claustrophobic, warm, and stuffy with a malfunctioning air conditioner and hornets outside the window.
Also be warned that if you are a single woman, you should travel cautiously in Mestre. My wife and I were traveling together and felt some measure of comfort in numbers, but I saw many dangerous and lascivious men at the bus/tram stops and on public transport. They were looking at my wife with hungry eyes, and I saw first-hand a man stalking a group of two young women waiting at a tram stop. If you are a single woman traveling alone, I would not recommend staying far from the train station in Mestre or going out alone at night.