Location, location, location. Lots of good cafes and restaurants in the surrounding blocks. Great ice cream just down the street at Juaja. Lots of busses a block away and the subway is only about four blocks. Safe area at night. Easy access to the various Palermo parks and museums. I think it's the best area in the city for a visitor to stay.
Spacious balcony with shade and a hammock. Friendly 24x7 security at the front door. The apartment that could use a few touchups but nothing that gets in the way of using it. It's an older, traditional apartment but everything works. The "on demand" water heater installed is quite common in older apartments and I find it a bit tricky to manage the water temperature in the shower compared to hot water tanks but maybe that's just me. Only one set of keys were available so make sure you make an arrangement with the host in advance if that's not going to work for you.
Did I mention it's in a great location with a huge balcony? The apartment gets four stars but the location gets six.