Martina and Walter have a lovely place and are very knowledgeable about Rome, its sights and how to get around them. They have me good tips which saved me time queuing in the hot sun. They're also lovely ppl who are always up for a chat (in perfect English too!).
Garbatella is a nice peaceful neighbourhood to base urself in and is actually really convenient for going to Ostia on a day trip.
Overall a great stay.