The flat is great! It really feels comfy and like you own home :) It is clean and one has everything one needs and can really enjoy at home, even when not exploring Rome, especially with a little terrace for yourself. Also, it is very well connected via public transportation although everything is really reachable by foot as well (especially of course Vatican just around the corner)! I found it very nice that the place is very calm and out of all the tourist noise.
In addition, Marco was very friendly, always reachable and flexible witch check-in and check-out so that was much appreciated.
I can only add that we really enjoyed our stay, the flat and Rome and would highly recommend it! :) Ciaoooo!