My husband and I stayed here for a few days for vacation. It was a good size for the two of us. I think it would be a bit cramped for more than two people, especially as you can only access the one bathroom via the bedroom.
Very close the the Colosseum and lots of great restaurants within a few blocks and public transportation. I also really appreciated how quickly I got responses to any questions/messages. And Irene let us check out late which was so, so helpful as our flight didn't leave until the evening. The apartment was also quiet which was very nice. And the air conditioning was so, so wonderful after being out in the hot August sun.
The kitchen is quite small and minimally equipped. But it worked for us as we didn't use it for much, other than storing a few things in the fridge. And the apartment was dark. This was good for sleeping, but during the day there wasn't much natural light inside. Also, the place did smell musty.