This flat is in the most superb location with the most fantastic view overlooking Campo dei Fiori that it almost made me cry multiple times. The flat has most everything you could want: a superb location, full (albeit incredibly small) kitchen, bathroom, an AC (thank the lord).
Some things to keep in mind: the flat is perfect for 2-3 people but the sofa bed is very uncomfortable. The shower is a bit odd in that there is no stand for the shower head and no shower curtain so the user must stand in the bathtub and guide the shower head by hand to take a shower whilst water splashes everywhere. The kitchen is small but equipped with everything you need - plates, utensils, pots and pans. However, the thing about this flat is that you must then the gas on and off (located underneath the sink) and then use a separate lighter to actual get some cooking started (or else it will just be gas with no light). The climb upstairs (the flat is on the top floor) is very difficult but the view alone makes it worth it!!! Food and wine tastes so much better when eating outside with this superb view, for sure.
Apart from a little misunderstanding regarding a private taxi, which was resolved between Sonia and I, I would say Sonia is an accommodating host who was flexible about the check in and check out time. Additionally, she seems to be living in the building next door which was very helpful when we forgot our keys and locked ourselves out of the flat (we were all just so happy to be in such an incredible location we were eager to explore and forgot). All in all, highly recommended.