Mara has a really nice apartment. It's close to the city, but really quiet inside. It has airco, a balcony, a little kitchen. And you can have your workout on your holiday since it's on the 5th floor (but also has an elevator if you've walked enought through the beautiful streets of Rome).
We visited with 3 couples, we all had our own room and bathroom, so a lot of space and privacy if needed. I would stay here again when travelling with 6!