We were on the Aria Amazon with a university alumni travel program, so everyone on the boat was with our group. I mention this mostly because the excursions and day-to-day activities were enhanced by knowing everyone. People without an interest in getting to know the other passengers might find the social nature of these cruises a bit daunting.
We arrived in Iquitos by plane from Lima--and returned that way. Then by bus to and from the Aria Amazon upon embarkation and disembarkation...
We were all adults--no kids. I believe the Aria does not take children under 7, and I can see why: the nature of the daily excursions would be less interesting for younger people.