First of all, Roberto's apartment looks absolutely amazing. You can tell a lot of thought went into the design and overall look of the place.
It's also spacious. We were two people, but with 2 bedrooms and 2 bathrooms, you can fit a small family in there. The wifi-signal was very poor on the second floor, though (where the bedrooms are).
The location is very central. It's about a 10 mins. walk to get to the historical center of Palermo.
We were greeted at the bus stop by a very helpful friend/colleague of Roberto when we arrived, which was appreciated.
All in all, I would highly recommend this place.