Antonio's apartment is absolutely beautiful - we were blown away when we walked through the front door and loved staying here. We only got to meet Antonio briefly but he was super lovely in person, really friendly and down-to-earth. Antonio will offer you an option of getting a private car transfer from the airport to the apartment - I would strongly recommend doing it as the apartment would not be that easy to find the first time and our driver not only dropped us off but ensured we knew exactly where to go to find the apartment and buzzed up to let Antonio's neighbour (who was welcoming us) know that we had arrived.
The apartment itself is in the most wonderful old building full of character. There are a number of flights of stairs to get up to the top but they are easy ('wide and shallow' is how another review put it). The plant-filled terrace is amazing. There's also a cute private balcony with chairs for sitting and having coffee on. I wish we had had more time in Palermo just so we could have hung out at the apartment more!
The location is fantastic - it's right in the 'old quarter' and many of the main sights are easy walking distance and easy to find just up the main street. The little side street the apartment building is also has cool little shops and restaurants/cafes and feels very hip and fun.
We used Antonio's restaurant recommendations (there's a book in the apartment with descriptions of his favourite places) and they were all great - some very 'local' and not touristy at all which was super fun.
I highly recommend staying here and would happily stay here again.