Oh please. The Gritti, after its massive refurbishment, using Disney-style reproduction furniture, is certainly better than it was, but I found the service and the food to be abysmal, especially the food.
Il Palazzo at the Bauer has not changed in a decade or more. It is a very tired hotel and the staff seems to be overwhelmed by the number of tourists that descend upon it. I used to love this little place, but no longer.
The Cipriani has evolved into a weird mix of expensive retail outlets and curious F&B venues and, as with most of Belmond's (ex Orient-Express) hotels, the food is either inedible or, at the best, mediocre.
Venice is EXPENSIVE no matter where you stay, so if you are going to spend a ridiculous amount of money, then best stay somewhere that delivers in terms of room/suite quality, historic authenticity, service and food. Aman delivers in spades.