Three Dials is both cute and well-kept (a good combination), and its proximity to the metro is not something you can take for granted in Rome. The factor that really puts it over the top, though, is the host, Daniele. He was lovely, and approached the task of hosting with the kind of zeal we like to see. He genuinely seemed offended by the idea of cutting corners.
Home truths: *The street outside is quite busy, so even though the windows are new, there's a fair amount of traffic noise
*The living room doesn't provide much of a space for socialising
*One person can sleep on a sofa bed, but it would take up most of the living room