The location is really great! The colosseum is literally 5 minutes away. Viewing it at night is so beautiful! Best restaurants are in Trastavere. A short bus ride away. (Get tickets at Bar La Licata, about 5 minutes away). We never took the subway, but I think it is also pretty close.
When you are ready to leave from your vacation, be cautious that you have to have the key with you to open the bottom floor gate to exit the building. We almost messed up.
The apartment is 2 floors up. There is an elevator for luggage, but it is tiny. 33 stairs to get to the apartment. We got our exercise on our trip!
I would stay here again. But 3 people maximum. I will say, the beds are super comfy. And the AC and WiFi work extremely well!