We stayed in August and it was quite hot in Venice. The air conditioner in the room worked well while it was on, but we had to keep the door closed to maintain the cool temperature. With the vaulted ceiling and the dark red carpet, this made the space feel very small and uncomfortable. Unfortunately, it was too hot to enjoy the roof terrace.
With that being said, Stefano was very kind and easy to communicate with. His directions to the apartment were excellent. The location was perfect because of its proximity to the Rialto waterbus stop. Note that you will having to carry your suitcase up the 4 flights of stairs.
If you are simply looking for a place to sleep, this is a great value. If you are looking for a more luxurious/lounging experience, I would not recommend (at least in the summer anyway).