Overall this apartment worked for us (myself and my 9yo). This is my feedback based on the fact that I am "a regular" to Venezia, renting about every 4 to 6 weeks for stays from 1 to 2 weeks.

-Pros:
..Location (easy access from the airport, really important when you are rolling around suitcases, no bridges to cross over and 3mn from the airport boat "shuttle" allilaguna blu) as well as Calle Nuova, and the 2 main tourist venues of Rialto and St Marco.
..Space (the place is actually spacious for Venezia),
..Quiet (very, except for upstairs neighbors walking around, but that is to be expected in an apartment situation)
..Clean (even if the apartment itself could use some overall refreshments it is clean and well kept)
..Bed (the bed was extremely comfortable) I can not personally comment on the couch doubling as bed in the living space, but my daughter did sleep well on it however.
..Wifi (important for most travelers) worked well.

Cons:
..Kitchen (it is serviceable but might be a challenge to cook a proper meal in there, the equipment is heavily used and scarce with miss matched pots and pants, no real good cutting knives, and basic items such as fine salt, pepper, oil and vinegar were missing).
..Bathroom (there is a serious odor problem emanating from said area, again I've rented in Venezia quite a lot and have never encountered such problem before, in short it smells like sewer vapors and odors).

Overall, I will be going back, as for me location is key and it is ideally placed for my needs (I work on Murano, and catching the 4.1 and 4.2 are but a 3mn walk) but it might not be what everyone is looking for. I would recommend this apartment however. Check in and check out was really friendly and easy and if you are absolutely new to Venezia finding this place will be very very easy.