If air conditioning is essential for you, please ensure you get advance written confirmation that it is working fully from Ginevra, and on what terms i.e. any time restrictions?
We expected aircon to be available - it is listed as an amenity - and it was not. Ginevra said an engineer would attend, but if one did, they made no repair. The other room in the apartment had the same issue. We were provided with desk fans after notifying Ginevra, for which we were grateful.
Then, if a fully working shower is important to you, again please ensure Ginevra confirms it is fully operational for your stay. It provides scalding hot water which is very difficult to cool down without it becoming fully cold.
Previous reviews show that this problem had been outstanding for some time. It may still be a live issue for your stay - ask ahead.
Castello is a lovely area, quiet and mostly Italian. The apartment is within easy striking distance to both the Arsenale and the Giardini for the Venice Art Biennale. I’d have preferred to give an unreservedly positive review, but you should be aware of the shortcomings before making a booking. Your choice can then be informed.