We stayed at Cassaro 261 for 2 nights in the middle of our 2 week tour of Sicily. It was a lovely place to be based in the old town area, just a few minutes walk to most of the sights, plus many restaurants and bars very close by. The apartment itself was very spacious, modern and well presented. Alessandro was also really friendly and helpful, and made us feel very welcome.
The main downside with visiting Palermo by car is that much of city, especially old town, has restricted access (ZTL) zones. For tourists this is very challenging to manage, and the information available (or not available) can be very confusing. For this reason, we parked at the long stay car park by the central station and then walked to Cassaro 261, which was about a 15 minute walk.