We had a lovely stay at Concetta's apartment right in the center of Ortigia. The apartment is small, but ideal for 2 persons and has everything you need for your stay. Even a fast WLAN was available.
The two terraces are amazing - you have a 360 degree view over Ortigia and the sea to your left and right. On the other hand you are right in the middle of the old town and simply take the elevator down, walk for 2 minutes and have stores, supermarkets, cafés and restaurants at your disposal.
We had a little problem with the water in the beginning due to the strong rainfalls the days before. But Concetta was immediately available and had it solved. Overall we have to say we had a very great time here and would definitely recommend it for a stay in Siracusa.