I had a lovely stay. It is my very 1st Airbnb experience and it was fantastic. The host Massimo was very friendly, helpful and welcoming. No question was too difficult or annoying to him. The place was very cosy and nice and it felt pretty safe (in fact safer than staying in a hotel I feel). There's a lift so you don't have to worry about carrying your luggage up too many steps. There is however a small flight of steps to get to the lift (probably just about 10 or less?)
The location is fantastic. Takes me less than 30min to get to most places. The Metro station is just 5min walk away. It takes 20min walk or 15min by Metro (because you have to change lines from A to B) to the Colosseum, 15min by Metro Line A (Spagna station) to the Spanish Steps, 20min by Metro Line A (Ottaviano) to the Vatican Museum.
There are many eateries nearby so you won't go hungry. The Metro station is just 5min walk away. If you need a local (Italy) sim card, Vodafone is near the Metro station. A supermarket is 2 to 3min walk away. Bar Pompi which serves good Tiramisu (supposedly) is 5min away on the way to the Metro station.
There is a big sports shop 10min away or 1 metro station (S. Giovanni) away. Massimo recommended it to me because my shoes disintegrated in the 2nd day! (He is really helpful!)
Choose this place if you are looking for a home away from home complete with convenience.