We had a great long stay at Marco & Barbara's place in Palermo. It was perfect for us with plenty of space, well equipped and in a lovely location. It is easy to get to town (via scooter or walking), nearby supermarkets (there are several within a few minutes walk) and Mondello Beach (via bus, 20 mins).
Communication, check-in and anything we needed was very easy with Marco and Barbara (honestly we didn't need much because everything was so smooth).