The apartment was above and beyond our best expectations.
The location is also great:
Central Station - 25 min walk
Balaro market - 5 - 10 min walk
Norman Palace and garden with palms - across the street
Cathedral of Palermo - 3 min walk
Catacombe dei Cappuccini - 20 min walk
In essence all the touristic attractions are easily accessible.
Regarding Mario - he is an awesome host - very friendly and responsive.
Once we had no water for short period of time - he came quickly, explained the reason for that and brought us two day water supplies with some delicious palermitano food.
By the way the problem was caused by public utilities and was block wide, not any how related to him.
He is just such a nice and friendly person.
Anyway this was fixed soon so everything was alright.
Highly recommended!