Ale & Nau are wonderful hosts. They went out of their way to make our stay comfortable. The apartment is quite comfortable and we'll maintained and very clean. They made arrangements for us to get into the apartment even when we were late and she was in office.
Location is a bit outside the city. But you can get to the center easily by train or bus.
To get to the apartment, I would recommend taking the 437 bus from the stop opposite to rebibia metro station. The stop name is tor sapienza. Or there is a stop but earlier (I think it is called tiburtina, I am not sure) where you can save about 15 minutes. But you need to walk about 5 minutes either way. Safe bet is to get down in tor sapienza for the first time.
Definitely recommend staying with Ale & Nau. We had an awesome time staying with you guys.