My wife and I stayed at Ca'Rezzonico for 2 nights and couldn't have been happier. The location is extremely convenient, smack dab in between the train station and everything else you would want to do in Venice. There are plenty of little restaurants, cafes, gelaterie all around the apartment, so if you wanted to have a more low key time away from the extremely touristy spots, you can do that there. The host were very welcoming. The appartment is comfortable and stocked with a few very appreciated amenities, like coffee and water.
We reccomend and will be back.