We stayed at Cosimo's place for a week, and we were really sad to leave. This is by far the best place we have rented on Air BnB, and you will be hard pressed to find a better place on Rome. The location is perfect. You can walk everywhere, from the major monuments to the charming Trastevere quarter. But honestly the apartment is so beautiful that you may not want to leave. You have a breathtaking view of Rome from every window, the terrace is to die for and the entire place is simply and tastefully decorated. You will also have everything you will need for your stay, including a perfectly equipped kitchen.
Finally Cosimo is an amazing host. Excellent communication and always available. We hope we will have a chance to stay at this place again.