I can't recommend Patricia's and Giacomo's place enough. The space itself is so beautiful, and looks exactly like the pictures! Giacomo is such a great host, he made sure to let us know the best way to get to the apartment from the airport and was really speedy at communicating with us, making us feel at ease. He truly went above and beyond when he helped us book a table (at a restaurant he recommended) for my family as there was 10 of us (all meeting in Venice but staying in different places) and I was worried about there being space, given that it was the last weekend of the Carnival.
The location of the apartment is perfect! It's a 15 minute walk from St Mark's Square and as you are pretty much in the center of Venice anywhere is in walking distance.
Giacomo gave us some great restaurant recommendations and also places to site see / visit. We didn't get round to going to all of them, however, the places we did go to we were made to feel very welcome. The restaurants that Giacomo recommended were very well priced and avoided the typical tourist trap ones.
I can't wait to come back and see even more of Venice and I will definitely be staying here again! :)