Franco's appartment is indeed a short stroll to the Colloseum. Being in an old building, it never got warm in the appartment, due to the solid brick walls and ceiling, which is wonderful if you're intending to travel to Rome in warmer months. Easy access to bus stop right outside the door.
Franco is a wonderful host - fantastic communication and very accommodating in regard to check-in/check out. Even received a message from him after a few days to make sure everything was ok. Highly recommended!