Three words: book this place!
Marco is a charming and welcoming host and his apartment is in an insanely good location. Literally out the front door you have the best tiramisu, the best gelato and the best pizza that we tasted in our travels. It is seriously hard to choose from the enticing array of restaurants in your own street! The only limits are your wallet and your waistline (but there are plenty of very reasonably priced restaurants nearby). Everything from the Colosseum to the Basilica is within walking distance and being so close to Piazza Navona, there are always signs to guide you home - we didn't need to take a taxi or public transport during our 5 night stay.
The apartment itself is comfortable and warmly welcoming. We we travelling with a multi-generational group - from 14yrs to 70yrs and everyone was happy (although my 70 year old mother did find the loft stairs a little tricky).
Marco was so helpful and generous - he allowed us to leave our bags at the apartment on our last day until 4pm and also organised an airport service for us. He was full of helpful tips and information and responded quickly and efficiently when we let him know there was a leak under the kitchen sink.
Thanks Marco for a wonderful stay in beautiful Roma!