I’ve been to Venice before during which I also stayed in an Airbnb apartment for about the same price - Turquoise Studio is definitely far better.
The studio is about an easy 20 minute walk from San Marco square and is situated away from the crazy hoard of tourists in a more local but still lively part of town with a neighbourhood greengrocer on a boat and other local shops.
If you are visiting for the Biennale like me, this studio is just 5 minutes away from both Giardini and Arsenale.
The studio was very clean and well furnished. I especially appreciated the dining recommendations - I tried two of them and they were great!
You will need to walk up to the third floor, so take note (but this also means fewer mosquitoes which are common in Venice!)
Also, the nearest vaporetto line can get very crowded so you should allow ample time when arriving and departing with luggage as you may need to wait for the next boat. I walked all over the main island otherwise, but it would be too challenging with luggage due to the many bridges, maze of alleys and crowds!