Our stay at Mansarda Luminosa was excellent. Ombra was a kind, friendly, accommodating, and generous host- she rearranged her schedule to meet us and bring us to the apartment, gave us wonderful suggestions about things to do and fantastic places to eat, and was extremely kind and responsive in all of our interactions before and while we were staying at the airbnb. The apartment was super clean and more beautiful and spacious than we had thought; the washing machine was very helpful, the kitchen was beautifully done, and I would've loved cooking there if we had more time. We were the first guests to stay there from airbnb and everything worked beautifully without any problems. (It was also great to have the warmest showers of our entire time in Italy!) It's also a quick walk to anywhere in Venice- nothing was more than a 20 minute walk (including St. Mark's, the train station, etc.). If you stay, there's also a wonderful wine shop (Calle del Fumo, 5310) with interesting local wines in bottles and on tap(! these for 2-3€ per liter) run by Giulia, who was very friendly and helpful.
I would highly recommend staying here to anyone visiting Venice; it was the nicest place we stayed on our trip!