The place was great, bigger than it looks on the pictures, with everything you need. It was also nice and clean, a bit warm, but that can be adjusted with the air conditioning.
The flat itself is located in the city center, with lots of restaurants around, and basically you are sitting in the middle of all the sites you would want to see. Everything is max 15 mins of walks away.
We were very satisfied with the place (2 of us) and Raffaele even recommended some good restaurants and sights to see - in a very detailed and polite manner.
I want to say that as an 'extra' service, as we wanted to see Etna, he told us that one of his friends, Carlo (who welcomed us at the flat), organizes such trips, and we could try to reach out to him. So we did. We ended up with a wonderful tour (with car + hiking to the top) with a very fair price. Carlo has 15+ years of experience with tours, has good English skills, and is a very nice person altogether.
If you plan to visit, both the flat, and the tour is highly recommended.