I initially booked the 2-bedroom at Ca D'Oro VELA online and Daniela accepted the booking right away, at almost midnight the night before our trip. This was a real life saver for us because our HomeAway host cancelled on us with 12 hours advance notice, leaving us no place to stay in Venice. As it turned out, Daniela had forgotten that her Ca D'Oro guests had decided to stay an extra night, but she communicated with me until 3am to get this worked out. We ended up staying at their GG listing by Rialto Bridge the first night. The little bathroom was newly renovated and fantastic and the tiny kitchen was brilliant--it's practically a cupboard but opens up and has what you need. We only slept the night there, but overall the accommodations were fine. Note, however, that the one bedroom listing is actually a studio (due to the European/American inconsistency that Americans count bedrooms and Europeans count rooms) and the king size bed is actually a pullout couch that takes up the entire living space when it's pulled out. Still, the place was clean and comfortable. It gets very loud very early in the morning because of it's location right by the Rialto Bridge, but it's definitely in the city center.
Our stay at Ca D'Oro VELA was much more comfortable, on a quiet alley still close to water bus stops and the main areas of Venice. It is indeed two dedicated bedrooms, but it's also two rooms--meaning no living room. The king beds in this one are two double mattresses side by side, not uncommon in Europe and perfectly comfortable. The eat-in kitchen is a bit cramped but we still cooked/ate in it two nights with no problem. Daniela's communication was superb, and her husband, also very friendly, met us promptly to give us the keys and guide us to the other apartment after the first night. All in all a very good experience. And the wifi worked well in both properties--which was a must for us!