This is a great flat in a superb location (about a 1 minute walk from Piazza Navona) and we walked all over Rome from it. It was clean, spacious and very well equipped (Sky TV, wifi, multiple coffee makers, etc.) Although it stated there was no lift, there actually was a small one which was handy on the first day with luggage.
This was an entire flat rental, so the hosts were not in residence, as we expected. This suited us perfectly as we were a group of nine wanting our own space. We were greeted and the workings of the flat explained on the first day and the hosts were just a phonecall away (perfect English) when we couldn't work out the heating. The transfer service they provided from the airport was very competitive and worth sorting out ahead of time.
This is a great property and I would thoroughly recommend it. This is the first Airbnb rental we have done and would do so again.