We stayed just one night here in Syracuse. The apartment is in a fantastic location - you can walk around the island easily. It's also really close to the lido / rocks where you can swim in the sea which is fun. Also check out the market about 15 minutes away - it's great fun. There is also a great little restaurant - turn right and right again out of the front door.
We didn't use the terrace but the wifi was fine. Check in was a bit complicated with Daniele's mum going to another apartment they own - so we were probably standing around for around 45 minutes waiting for her. Other than that everything was fine. The only thing I would say is for a one night stay it's quite expensive (but the location is excellent) due to the other fees.