Location, location, location! Literally above the Rialto Market, you're not going to find a better spot than this. You're a 10 second walk from the market, a 30 second walk from a half dozen places to eat and drink. And you're a 60 second walk from the vaporetto stop.
Michela was very quick on the replies and had an entire book printed out with maps giving us guidance on where to eat and shop for groceries. I would definitely stay here again.