The location is good, and the apartment faces away from the road, so doesn't pick up street noise. It was quiet for my stay, which was important to me.
It has AC, and whilst it's not in the bedroom, it does partially cool the bedroom. However, because the apartment doesn't get a lot of direct sunshine, with the AC working, temperature wasn't an issue.
Unfortunately when I arrived there appeared to have been an issue with the cleaning. For example, someone had shaved in the bathroom, and not cleaned the hairs from the sink. The bed was full of body hairs, and appeared not to have been changed. The floor and fridge were very dirty, etc. After informing Guillermo, he arranged to have it cleaned, and sent round fresh bed sheets for me to put on. I waited in for the cleaner, and she agreed the place was in a bad state. Fortunately, once it was cleaned again, and I had changed the bed sheets, it was back up to an adequate standard. Honestly, I had expected more, given how much I was paying.
Few things to note - the washing machine doesn't work. Also there are 2 elevators, but only 1 worked during my stay. The second elevator broke the last day I was there, so I had to carry my heavy suitcases down the stairs. Presumably it will have been fixed by now! Some aspects of the apartment look a bit worn out, for example the AC has leaked and damaged the wall, but this hasn't yet been repaired.
Assuming no future issues with the cleaning, the apartment is in a good location, is quiet, and has most of what you need for a good stay in Palermo.