Marco's place is very central to all of cantania. It was a quick and easy 15 min drive from the airport and about an hour drive to Mt. Etna. There is free parking all around his place. (Make sure not to park in the blue area though because that is paid parking) The downtown area and duomo is about a 10 min walk and there are many places to eat and drink there.
Across the street is a large, beautiful park with lots of greenery, water fountains, and places to relax. This park connects you to the heart of town and the most delicious arincino place in Sicily called "savia bar." (Marco's recommendation)
Marco went above and beyond to make sure we had a nice stay. He was an excellent host and will help you with any problems you have. His English is near perfect too.
The apartment is on the ground level and features good wifi, a full functioning kitchen, stove, oven, dishes, pots and pans. We made breakfast every morning, and also a few dinners. The bathroom was clean and the shower was hot. We had an amazing time at marco's place and enjoyed Catania immensely.