We stayed at this apartment for 3 nights and had a perfect stay! The apartment is huge, comfortable and had everything we could have needed. The view from the roof terrace will leave you speechless! As other guests have mentioned, the walk up the apartment can be a bit challenging after a long day of touring, but it's worth it! The air conditioning is very effective and even though we chose to leave it off while we were out for the day, it very quickly cooled the apartment when we arrived back.
Orsola was extremely accommodating, particularly since we arrived on an early train and the recommendation for restaurants provided with the apartment was the favorite meal of our trip! I will mention that the stairs to the terrace only have a railing on one side, so if you are traveling with young children, you will need to be cautious. There is a door to the bedroom and our 6 year old was fine, but you would need to be careful with a curious 2 or 3 year old.
The location of the apartment is great! Easy walking distance to Piazza San Marco and the other sites, but far enough away that there aren't the tourist crowds, which made it very peaceful. There is a grocery store very close that had everything you could need. Overall, our favorite place we have stayed!