(1) The location - perfect. It is just about 5 min from St.Marco, but on a very quiet side street, so the passing crowds do not affect your sleep.
(2) The rooms - nice, larger than from what I have previously experienced in Venice, a well-equipped kitchen and air conditioning in all rooms but one. And a very nice terrace upstairs!
(3) The organizational matters - easy to reach from the airport by vaporetto, just 5-6 minutes away from the stop. Pick-up and drop-off of keys at a nearby hotel with friendly people who took us to the apartment.
All in all, this is where I would gladly return for another Venice trip.