You may want to consider the two Sheratons in Rome as an alternative. The Sheraton Golf is a category 2. It is the Starwood property closer to the FCO airport, and you will be spending more time going downtown than at other hotels.
I was there only one night about a month ago and I was reasonably pleased with it. I had a room in the main building but it looked like the rooms in the smaller buildings near the pool would be nicer.
I liked the Sheraton Rome slightly better but the Sheraton Golf would be a better value for your points.