I had an interesting experience on Mr. Moretti place. The main advantage of staying here is, in my view, his welcome and briefing about Catania and the places to visit around, the flexibility of checking-in and out, his local tips on how to do certain things (example. How to best hike the Mt. Etna) and the extensive range of equipment that Marco makes available for his guests for free (bicycle, swimming equipment, beach accessories, books, maps, shoes... you named it!).
And last but not the least: The location and the vintage feel of an old and grandeur palazzo contributes for a local experience.
On the less positive side, the apartment can feel a bit untidy and cluttered and has some reviewers have noted previously, this is by far not the cleanest flat ...but I had my expectations adjusted for the price of 10Euros a night so you clearly got what you pay for.
Also the Kitchen is tiny and it was very dirty throughout my stay, probably due to some other less rigorous guests but that can happen when you share the flat with two other rooms.
I stayed in the single room which was of a decent size but the two mattresses piled on each other meant it was not the most comfortable bed I slept in. It does not get flat and considerably sinks in the middle. Also as you naturally move while you sleep the top mattress also tends to move so it gets misaligned..
If you are restricted in your budget and for a 1-3 nights, I can actually recommend staying here, being conscious of the overall flat's cleaning standard.
I even helped Marco washing my bed sheets with soap and hot water and to put then to dry in the balcony :)