We stayed at Hotel Guerrato for three nights last month. Location is great - next to the Rialto market, with fresh fruit stalls right at the door. Walking distance to all main attractions. Breakfast was the best we got in Italy (we went through ten cities): full buffet, eggs, bacon, fruit salad, a la carte hot drinks, etc. Our quadruple room was massive and decorated in Venetian style. The extra beds were simply pullout chairs - but even then, more convenient than we got in other hotels. Definitely not cheap, but I had no regrets choosing this place: solid positive experience.