We stayed 1 month at Valeria's flat and it was very pleasant. She's a very nice host and helpful.
Pros: Sparkling clean. The flat has been recently remodeled. Very well equipped with premium appliances. Perfect location near piazza della Repubblica (Termini train station is at walking distance but it's also near Monti, the Borghese gardens etc..). Very nice building with high ceilings. Bed is very comfy.
Cons: Poor wifi (4 Mb/s, it may be not enough is you need to work there) and cellular coverage (because of thick walls and ground floor situation). Not direct sunlight because it's on ground floor.