Mauro was very responsive and kind from the very beginning. He gave us tips about how we can find the location easily.
The apartman is like in the pictures, it was very clean and well-equipped.
It is a ~15-20 minutes walk to the Colosseum, but there is a nearby metro station as well so we could get to Vatican without any problem.
Since we did not speak Italian, when we left I asked Mauro if he could order a taxi for us, he did it without hesitation.
Nice apartman, very kind host, would recommend.