We really enjoyed our stay at this place, which is really well located in Ortigia.
The flat in itself is quite charming and well decorated. The sea is 15 meters away from the window...
The AC really proved to be useful.
The electricity might go down a few times if you don't know precisely how much power you're using, especially in summer with the AC on, but it's quite easy to put back on. It was the only slight inconvenience that we faced during our stay, everything else was fine.
It also is quite hard to park a car in Ortigia, especially in the evening, and in the high season every parking lot is occupied, so you can expect to walk a bit.