Antonio's place is great for exploring Ortigia. It is in the charming Jewish quarter, only 3 minutes walk from a swimming spot. I also recommend the free tour of the underground tunnels under the church around the corner.
There is no Airco, but there are three fans, which is sufficient in most weather. The place has few windows, but in my experience that can be a plus for keeping the heat out. The apartment has a door straight into a charming little alley.
Antonio lives next door and was extremely helpful and reacted very fast. He solved a small plumbing issue very promptly.
I would definitely recommend staying at Antonio's place to anyone wanting to explore Ortigia and experience its charming atmosphere and delicious food.