We were pretty happy with this apartment overall. Location was nice being a block off the Trastavere to Campo dei Fiori route (handy, but a bit quieter than being in the middle of things). The apartment is in decent shape, though some bits were a little quirky. Not as spacious feeling as the size might indicate, as the space was chopped with a bunch of hallways, but still quite nice for 3-4 people. The elevator was nice to have, though the manual doors take a little getting used to. Air conditioning is only in the front two rooms; the back bedroom opened on the Spada palace garden, though, so pretty quiet if you had the window open.
I wouldn't hesitate to stay here again. If you could take the space and knock down some walls and remodel to modern standard, it would be great (but probably rent for twice as much).