Rossana was very helpful and fast in responding; the apartment is exactly as described; see also the other reviews. The only minus is the location at a busy road, also at night, which means that windows can't be open for sleeping, and even with closed windows, it's pretty noisy in the downstairs sleeping room. I slept very well upstairs on the converted sofa, which I found quite comfy.
From a strategic point of view, the apartment is quite well positioned: directly opposite of the bus stop to go to Monreale, a few steps to the Porta Nuova, where the old city centre starts, including the Palazzo Reale. On this short way, you also find a taxi stop, where we never had to queue to get a taxi.