We stayed at Alessandro's Bed 'n' Breakfast - which appeared more like a small hotel to us - for three days and enjoyed it very, very much. Alessandro renovated the whole place a few years ago; it only has four rooms, so there is a nice, personal atmosphere. As far as our own room was concerned, it looked exactly as it appeared in the picture on the internet, including the jacuzzi in the bathroom.
Alessandro is an extremely kind host, always ready to provide his guests with general advice and (valuable!) insider tips. Breakfast was included in the room rate and consisted of fresh bread and croissants from the local bakery, fruit, cheese, coffee, tea, etc. The BnB is located in the Rialto neighborhood, in easy walking distance to all the attractions.
The one (small) drawback was that sound insulation at the BnB was not great - we could often hear other guests and the workers outside; however, this was a problem that we encountered in most other places in Italy as well, so it should not keep you from choosing Alessandro's place to stay.
All in all, we had a great time at this BnB, would go back in a heartbeat if we were to return to Venice, and would recommend it without reservations to any of our friends. Thanks a lot, Alessandro!