No question that the Terrace is a ringside seat along the Grand Canal. If just going for an afternoon cocktail and wanting something light to eat, such as salad or sandwich, sit just outside of the bar and order the bar menu. It is a smaller terrace than the large one used for fine dining. Same great view. Should mention that there is a new hotel almost directly across from the canal with same view.
The Centurion. We had lunch there in October. Great food, view and service. Toured hotel but I'll write about that on different thread. FYI, canal view rooms are gorgeous.