We stayed here for three nights while visiting Palermo. I would recommend this place for those who seek for living in the center - you can reach most of the Palermo sights withing minutes.
Of course, living in the middle of the market has its own disadvantages - it gets not that cosy getting back home, especially at nights. It is quite loud in the streets as well, so for those seeking a calm place this would not be an option.
The apartment itself is small and suitable for a short stay. It has a flexible checkin option with the keypad.
I would say, that the value is quite reasonable. If you are used to crowds of people and a lot of action during the whole day and night and ready to experience Palermo from its core, this might be an option for you.