Me and a friend recently visited Sicily (end of May/early June) and Palermo was our first stop jet lag and all. Quinto Canto is in a great central location especially if you are only staying for a couple of days. Everyone was very helpful suggesting some "must sees" as soon as we checked in and providing suggestions for a close by lunch. We also tend to have A LOT of questions when we travel and everyone was really patient and kind.
The hotel styling is pretty cool with some modern touches like the bathroom, but also a lot of character. Our room wasn't huge, as expected for a city hotel, but was easy to use. The breakfast buffet was great and there is a nice little courtyard attached to the restaurant. We didn't have time to enjoy the spa so no comments there.