Nicola and Maria Grazia are definitely very good hosts.
when my friend and i arrived they gave us a lot of advices to have a great time in Catania. They also advised us a very good restaurant very cheap. their home is very well located (at a 2min walk from a supermarket and at a 10min drive from the center).
they left us the fridge full of food so that we didn't have to spend to much on groceries.
we had a wonderful time there, we definitely recommend.