Hard to overestimate how wonderful the location is--it is just a two minute walk from San Marco and ten minutes (max) walk from Rialto and its wonderful food markets (if you want to cook). The convenience of being near San Marco is high -- for vaporetto, taxis, shuttles, etc. as well as ease of finding your way (there are many signs throughout Venice that help you find your way back).
Yes, this is an area of high tourism, but the apartment is truly a quiet oasis in the midst of this. The balcony is sunny all day and even nicer than it appears in the pictures. We stayed here for eight nights and loved it. Nicola met our boat, helped with our bags, and was always justs a Whatsapp away.