The apartment is far enough away from the city core, that it is not overwhelmed by tourists, and it's close enough to the attractions and city core for walking / bus / tram.
It is worth it to walk from the apartment to the city core, even if it takes 30 - 40 minutes. You will be walking through the beautiful Trastevere, which is famous for good restaurants, small cozy alleys and beautiful buildings. If you don't feel like walking that much, the tram connection is good. Tram number 8 goes back and forth all the time, and it cost 1,5 €.
The hosts have some good deals you can use, or not. They are not pushy.
We got picked up at the airport for 40 € (Fiumicino), and the Über cost around 50 €.
It's cheaper with the train, but that require some walking and waiting.