I first stayed at Giovanni's Rialto Dream location. Very good location for visiting several tourist attractions, including the fish market, the Rialto bridge, Fontego dei Tedeschi, and many, many shops and restaurants. I tried two restaurants that Giovanni recommended and 1 bakery. All were good. The bathroom at this location was small, in my opinion, but overall it certainly serves the purpose. Giovanni was in great communication, gave good directions, met me and carted my suitcase from the boat ramp to the apartment.
I next stayed at Giovanni's St. Marco location (I can't remember the name of it). It too was in a great location for everything in the St Marco Square area. Again, Giovanni schlepped my suitcase to the new location and spent a good amount of time explaining everything in the apartment to me and showing me on a map where everything I wanted to see was. I very much appreciated the larger bathroom. Beautiful courtyard entrance and a short, straight shot to the water taxi to the train station (or anywhere else you want to go).