Loved: the views, the terraces, the sunlight, the layout that allows privacy if people wake up at different hours, for instance. Nice living area with comfy corner sofa and corner panoramic window, separate dining area with terrace doors, great mattress and pillows in the master (we didn't test the other beds), and good quality sheets. Good, central location (we walked everywhere, and there are plenty of taxis one minute walk away).
Did not love: the apartment is a bit tired and scuffed, and the building not well maintained, the kitchen needs a bit more equipment (salad bowl, paper towels for instance), we couldn't make the bedroom TV work. But we enjoyed the place and loved coming back there after hours of trekking around Rome, it has a great vibe.