Nice apartment, nice people and very clean. The Vatican is on walking distance (about 20 minutes), but just around the corner there are also several busses you can take to the city centre or the Vatican. If you are with more than two persons I strongly recommend to use the taxi service, because it is cheaper and of course faster than public transport. With two persons it is € 12 (excluding tip) more than the costs for public transport if you take the Leonardo Express train.